| 1998 | 1999 | 2000 | |||||||||||
| Less than 13 Months | 13 to 24 Months | More than 24 Months | Unknown | Less than 13 Months | 13 to 24 Months | More than 24 Months | Unknown | Less than 13 Months | 13 to 24 Months | More than 24 Months | Unknown | ||
| 2,561 | 995 | 998 | 174 | 2,905 | 926 | 1,298 | 0 | 3,414 | 927 | 1,145 | 0 | ||
| Year | Under 13 | 13 to 24 M | Over 24 Months | ||||||||||
| 1996 | 2,461 | 758 | 1,544 | ||||||||||
| 1997 | 2,993 | 768 | 1,648 | ||||||||||
| 1998 | 2,561 | 995 | 998 | ||||||||||
| 1999 | 2,905 | 926 | 1,298 | ||||||||||
| 2000 | |||||||||||||