loop returns 0 when trying to count points between limits

I am trying to return the number of points of a set of continuous time series data using nCode glyphworks, the variable points_IL returns 0, I need it to return the number of points between the lower and upper limit, the application specific code is correct, could someone look at this code and suggest some improvement/fix

i=0
while i<Point_Count:

        Point_Val = tsin.GetValue(Single_TAL_Index,i)

        es.JournalOut(str(Point_Val))
        if  Lower_Limits[locate_chan]<=Point_Val<=Upper_Limits[locate_chan]:
            Points_IL+=1
        i+=1

    es.JournalOut('number of points in the limits')
    es.JournalOut(str(Points_IL))