Age group/year | Frequency | Cumulative frequency | Cumulative % |
<30 | 18 | 18 | 6.16 |
31 - 40 | 80 | 98 | 33.56 |
41 - 50 | 101 | 199 | 68.15 |
51 - 60 | 48 | 247 | 84.58 |
61 - 70 | 31 | 278 | 95.2 |
71 - 80 | 13 | 291 | 99.65 |
>80 | 1 | 292 | 100 |