fname = 'f:\\питон\\dataset_3380_5.txt'
ClassQuantity = 11
Table = dict()

ArrayOfHeight = [0] * ClassQuantity
ArrayOfAmount = [0] * ClassQuantity

InfoFile = open(fname, 'r')
for line in InfoFile:
    s = line.strip().split('\t')
    s[0] = int(s[0])

    ArrayOfAmount[s[0] - 1] += 1
    ArrayOfHeight[s[0] - 1] += int(s[2])

InfoFile.close()

for i in range(ClassQuantity):
    if ArrayOfAmount[i] == 0:
        print(i + 1, '-')
    else:
        print(i + 1, float(ArrayOfHeight[i] / ArrayOfAmount[i]))