First number (left of decimal)= male 1.0
Second number (right of [first] decimal) = female 0.1
Third number (if there is one--right of second decimal) = unknown sex 0.0.1
Examples:
1.0 = 1 male
0.1 = 1 female
1.1 = 1 male, 1 female
2.1 = 2 males, 1 female
0.0.1 = 1 unknown sex
1.1.1 = 1 male, 1 female, 1 unknown sex
1.1.2 = 1 male, 1 female, 2 unknown sex
Hope this clears things up.