import codecs

with codecs.open('text.txt', "r", "utf-8-sig") as handle:
    numbers = []
    count = []

    for i in range(24):
       numbers.append(float(0))

    for i in range(24):
       count.append(float(0))

    for line in handle:

        lineSplit = line.split()

        fieldOne = lineSplit[0]
        numOne = fieldOne.split('.')[0]

        fieldTwo = lineSplit[len(lineSplit)-1]
        numTwo = fieldTwo.split('/')[0]

        numOne = int(numOne)
        numTwo = float(numTwo)

        count[numOne-1] = count[numOne-1] + 1

        numbers[numOne-1] = numbers[numOne-1] + numTwo

    for i in range(24):
        numbers[i] = numbers[i]/count[i]
        print str(i+1) + ": " + str(numbers[i])


Results:

1: 7.76923076923
2: 7.99545454545
3: 8.17916666667
4: 8.27727272727
5: 8.35
6: 8.38
7: 8.336
8: 8.216
9: 7.904
10: 7.65652173913
11: 7.39090909091
12: 7.42380952381
13: 7.15909090909
14: 7.03636363636
15: 7.05454545455
16: 7.13333333333
17: 7.03636363636
18: 7.20454545455
19: 7.095
20: 7.01904761905
21: 7.02173913043
22: 6.99090909091
23: 7.04545454545
24: 7.0375