R : making if and for statements simpler

select3_sum <- 0
select3_subsum <- 0
select3_compare <- 0

for (j in 1:5025){

  select_index[j,18] <- 0 
  select3 <- 0 
  for(i in 1:13){
    select3_subsum <- 0 


    for(k in i+1:14){
      select3_compare <- select_index[j,i]
      select3_subsum <- select3_compare 

      for(a in k+1:15){
        denon <- 1 

       if(select3_compare <= select_index[a,l]){
         select3_compare <- select_index[a,l]
         denon <- denon+1
         select3_subsum <- select3_subsum+select3_compare
       }
        select3_sum <- select3_sum + (select3_subsum/denon)
      }

      if(select3_compare <= select_index[j,k]){
        select3_compare <- select_index[j,k]
        denon <- denon+1
        select3_subsum <- select3_subsum+select3_compare 
      }
      else{
        select3_subsum <- select3_subsum
      }

      select3_sum <- select3_sum + (select3_subsum/denon)
    }
  }
  select3 <-(select3_sum/choose(15,3)) 
  select_index[j,18]<- select3
  select3_sum <- 0 

Here is what I gave up for cases of three countries.

data is like below

structure(list(V1 = structure(c(2L, 1L, 1L, 1L, 1L, 1L, 1L), .Label = c("6", 
"CHILE.index"), class = "factor"), V2 = structure(c(2L, 1L, 1L, 
1L, 1L, 1L, 1L), .Label = c("6", "SINGAPORE.index"), class = "factor"), 
    V3 = structure(c(2L, 1L, 1L, 1L, 1L, 1L, 1L), .Label = c("7", 
    "EFTA.index"), class = "factor"), V4 = structure(c(2L, 1L, 
    1L, 1L, 1L, 1L, 1L), .Label = c("6", "USA.index"), class = "factor"), 
    V5 = structure(c(2L, 1L, 1L, 1L, 1L, 1L, 1L), .Label = c("7", 
    "ASEAN.index"), class = "factor"), V6 = structure(c(2L, 1L, 
    1L, 1L, 1L, 1L, 1L), .Label = c("7", "INDIA.index"), class = "factor"), 
    V7 = structure(c(2L, 1L, 1L, 1L, 1L, 1L, 1L), .Label = c("7", 
    "EU.index"), class = "factor"), V8 = structure(c(2L, 1L, 
    1L, 1L, 1L, 1L, 1L), .Label = c("7", "PERU.index"), class = "factor"), 
    V9 = structure(c(2L, 1L, 1L, 1L, 1L, 1L, 1L), .Label = c("7", 
    "TURKEY.index"), class = "factor"), V10 = structure(c(2L, 
    1L, 1L, 1L, 1L, 1L, 1L), .Label = c("7", "COLOMBIA.index"
    ), class = "factor"), V11 = structure(c(2L, 1L, 1L, 1L, 1L, 
    1L, 1L), .Label = c("7", "AUSTRAILIA.index"), class = "factor"), 
    V12 = structure(c(2L, 1L, 1L, 1L, 1L, 1L, 1L), .Label = c("6", 
    "CANADA.index"), class = "factor"), V13 = structure(c(2L, 
    1L, 1L, 1L, 1L, 1L, 1L), .Label = c("7", "NEW ZEALAND.index"
    ), class = "factor"), V14 = structure(c(2L, 1L, 1L, 1L, 1L, 
    1L, 1L), .Label = c("7", "VIETNAM.index"), class = "factor"), 
    V15 = structure(c(2L, 1L, 1L, 1L, 1L, 1L, 1L), .Label = c("7", 
    "CHINA.index"), class = "factor"), V16 = structure(c(2L, 
    1L, 1L, 1L, 1L, 1L, 1L), .Label = c("0", "select1"), class = "factor"), 
    V17 = structure(c(2L, 1L, 1L, 1L, 1L, 1L, 1L), .Label = c("0", 
    "select2"), class = "factor"), V18 = structure(c(2L, 1L, 
    1L, 1L, 1L, 1L, 1L), .Label = c("0", "select3"), class = "factor"), 
    V19 = structure(c(2L, 1L, 1L, 1L, 1L, 1L, 1L), .Label = c("0", 
    "select4"), class = "factor"), V20 = structure(c(2L, 1L, 
    1L, 1L, 1L, 1L, 1L), .Label = c("0", "select5"), class = "factor"), 
    V21 = structure(c(2L, 1L, 1L, 1L, 1L, 1L, 1L), .Label = c("0", 
    "select6"), class = "factor"), V22 = structure(c(2L, 1L, 
    1L, 1L, 1L, 1L, 1L), .Label = c("0", "select7"), class = "factor"), 
    V23 = structure(c(2L, 1L, 1L, 1L, 1L, 1L, 1L), .Label = c("0", 
    "selec8"), class = "factor"), V24 = structure(c(2L, 1L, 1L, 
    1L, 1L, 1L, 1L), .Label = c("0", "selec9"), class = "factor"), 
    V25 = structure(c(2L, 1L, 1L, 1L, 1L, 1L, 1L), .Label = c("0", 
    "selec10"), class = "factor"), V26 = structure(c(2L, 1L, 
    1L, 1L, 1L, 1L, 1L), .Label = c("0", "selec11"), class = "factor"), 
    V27 = structure(c(2L, 1L, 1L, 1L, 1L, 1L, 1L), .Label = c("0", 
    "selec12"), class = "factor"), V28 = structure(c(2L, 1L, 
    1L, 1L, 1L, 1L, 1L), .Label = c("0", "selec13"), class = "factor"), 
    V29 = structure(c(2L, 1L, 1L, 1L, 1L, 1L, 1L), .Label = c("0", 
    "selec14"), class = "factor"), V30 = structure(c(2L, 1L, 
    1L, 1L, 1L, 1L, 1L), .Label = c("0", "selec15"), class = "factor")), .Names = c("V1", 
"V2", "V3", "V4", "V5", "V6", "V7", "V8", "V9", "V10", "V11", 
"V12", "V13", "V14", "V15", "V16", "V17", "V18", "V19", "V20", 
"V21", "V22", "V23", "V24", "V25", "V26", "V27", "V28", "V29", 
"V30"), class = "data.frame", row.names = c(NA, -7L))

I'd like to calculate the average of accumulation of index(accumulate in case it is same or over, if not then it is not included in calculation)

I've already got results for cases when the number of countries is one and two. the results is like below.

structure(list(X = 1:3, CHILE.index = c(6L, 6L, 6L), SINGAPORE.index = c(6L, 
6L, 6L), EFTA.index = c(7L, 7L, 7L), USA.index = c(6L, 6L, 6L
), ASEAN.index = c(7L, 7L, 7L), INDIA.index = c(7L, 7L, 7L), 
    EU.index = c(7L, 7L, 7L), PERU.index = c(7L, 7L, 7L), TURKEY.index = c(7L, 
    7L, 7L), COLOMBIA.index = c(7L, 7L, 7L), AUSTRAILIA.index = c(7L, 
    7L, 7L), CANADA.index = c(6L, 6L, 6L), NEW.ZEALAND.index = c(7L, 
    7L, 7L), VIETNAM.index = c(7L, 7L, 7L), CHINA.index = c(7L, 
    7L, 7L), select1 = c(6.733333333, 6.733333333, 6.733333333
    ), select2 = c(6.804603175, 6.804603175, 6.804603175), select3 = c(0L, 
    0L, 0L), select4 = c(0L, 0L, 0L), select5 = c(0L, 0L, 0L), 
    select6 = c(0L, 0L, 0L), select7 = c(0L, 0L, 0L), selec8 = c(0L, 
    0L, 0L), selec9 = c(0L, 0L, 0L), selec10 = c(0L, 0L, 0L), 
    selec11 = c(0L, 0L, 0L), selec12 = c(0L, 0L, 0L), selec13 = c(0L, 
    0L, 0L), selec14 = c(0L, 0L, 0L), selec15 = c(0L, 0L, 0L)), .Names = c("X", 
"CHILE.index", "SINGAPORE.index", "EFTA.index", "USA.index", 
"ASEAN.index", "INDIA.index", "EU.index", "PERU.index", "TURKEY.index", 
"COLOMBIA.index", "AUSTRAILIA.index", "CANADA.index", "NEW.ZEALAND.index", 
"VIETNAM.index", "CHINA.index", "select1", "select2", "select3", 
"select4", "select5", "select6", "select7", "selec8", "selec9", 
"selec10", "selec11", "selec12", "selec13", "selec14", "selec15"
), class = "data.frame", row.names = c(NA, -3L))

How can I make codes to calculate all cases(the number of countries from 1 to 15) without being too complex?