Age group | n | Mean | Standard deviation | Median | P |
---|---|---|---|---|---|
<21Â years | 21 | 1.43 | 1.287 | 1 | <0.001 |
21-30 years | 268 | 2.05 | 1.107 | 2 | Â |
31–40 years | 520 | 2.36 | 1.133 | 2 |  |
41–50 years | 283 | 2.11 | 1.203 | 2 |  |
51–60 years | 183 | 1.98 | 1.160 | 2 |  |
61–70 years | 110 | 1.85 | 1.060 | 2 |  |
71–80 years | 52 | 1.33 | 0.985 | 1 |  |
81–90 years | 7 | 1.00 | 1.000 | 1 |  |
>90 years | 1 | 0.00 | – | 0 |  |
Total | 1445 | 2.11 | 1.164 | 2 | Â |