5-year age bands
1 = 0-4
2 = 5-9
3 = 10-14
4 = 15-19
5 = 20-24
6 = 25-29
7 = 30-34
8 = 35-39
9 = 40-44
10 = 45-49
11 = 50-54
12 = 55-59
13 = 60-64
14 = 65-69
15 = 70-74
16 = 75-79
17 = 80+