Create a dictionary using "if... else" in Julia?

I'm working with a sample CSV file that lists nursing home residents' DOBs and DODs. I used those fields to calculate their age at death, and now I'm trying to create a dictionary that "bins" their age at death into groups. I'd like the bins to be 1-25, 26-50, 51-75, and 76-100.

Is there a concise way to make a Dict(subject_id, age, age_bin) using "if... else" syntax? For example: (John, 76, "76-100"), (Moira, 58, "51-75").

So far I have:

#import modules
using CSV
using DataFrames
using Dates

# Open, read, write desired files 
input_file = open("../data/FILE.csv", "r")
output_file = open("FILE_output.txt", "w")

# Use to later skip header line
file_flag = 0

for line in readlines(input_file)
    if file_flag==0
        global file_flag = 1
        continue
    end

    # Define what each field in FILE corresponds to
    line_array = split(line, ",")
    subject_id = line_array[2]
    gender = line_array[3]
    date_of_birth = line_array[4]
    date_of_death = line_array[5]

    # Get yyyy-mm-dd only (first ten characters) from fields 4 and 5:
    date_birth = date_of_birth[1:10]
    date_death = date_of_death[1:10]

    # Create DateFormat; use to calculate age
    date_format = DateFormat("y-m-d")
    age_days = Date(date_death, date_format) - Date(date_birth, date_format)
    age_years = round(Dates.value(age_days)/365.25, digits=0)

    # Use "if else" statement to determine values
    keys = age_years
    function values()
        if age_years <= 25
            return "0-25"
        elseif age_years <= 50
            return "26-50"
        elseif age_years <= 75
            return "51-75"
        else age_years < 100
            return "76-100"
        end
    end
    values()

    # Create desired dictionary
    age_death_dict = Dict(zip(keys, values()))

end