| Year | Individual Registrations | Litter Registrations |
| 1979 | 5,558 | 1,506 |
| 1980 | 5,585 | 1,451 |
| 1981 | 5,482 | 1,489 |
| 1982 | 5,409 | 1,478 |
| 1983 | 6.032 | 1,592 |
| 1984 | 6,354 | 1,708 |
| 1985 | 6,880 | 1,810 |
| 1986 | 8,170 | 2,205 |
| 1987 | 11,291 | 2,930 |
| 1988 | 14,109 | 4,013 |
| 1989 | 17,488 | 5,217 |
| 1990 | 21,603 | 6,531 |
| 1991 | 30,225 | 8,558 |
| 1992 | 38,927 | 9,993 |
| 1993 | 42,816 | 11,414 |
| 1994 | 42,621 | 12,540 |
| 1995 | 36,714 | 12,596 |
| 1996 | 32,972 | 11,012 |
| 1997 | 22,726 | 8,662 |
| 1998 | 9,722 | 3,939 |
| 1999 | 4652 | NA |
| 2000 | 3084 | NA |
| 2001 | 2139 | NA |