Table 1. Details of the age groups used in the mathematical models.

Woodlands		Plains		All
Average age, years	Number of samples	Average age, years	Number of samples	Average age, years	Number of samples
1.1	22	1.5	14	1.1	26
2.0	22	2.7	14	1.8	26
3.5	22	5.5	14	2.5	26
6.8	22	8.7	14	4.2	26
10.7	26	11.6	14	6.9	26
				8.7	26
				12.0	28
Total	114		70		184