Historical Results Timeline
| Year | Date | Winning Total | Total Cumulative |
|---|---|---|---|
| 2008 | May 10 | 229 | 271 |
| 2007 | May 12 | 230 | 265 |
| 2006 | May 13 | 229 | 259 |
| 2005 | May 14 | 222 | 262 |
| 2004 | May 15 | 219 | 272 |
| 2003 | May 10 | 231 | 262 |
| 2002 | May 11 | 224 | 266 |
| 2001 | May 12 | 214 | 258 |
| 2000 | May 13 | 219 | 263 |
| 1999 | May 15 | 223 | 261 |
| 1998 | May 9 | 200 | 262 |
| 1997 | May 10 | 217 | 270 |
| 1996 | May 11 | 229 | 270 |
| 1995 | May 13 | 225 | 262 |
| 1994 | May 14 | 218 | 267 |
| 1993 | May 15 | 215 | 265 |
| 1992 | May 16 | 205 | 257 |
| 1991 | May 18 | 199 | 262 |
| 1990 | May 19 | 210 | 255 |
| 1989 | May 13 | 201 | 259 |
| 1988 | May 14 | 200 | 254 |
| 1987 | May 16 | 205 | 251 |
| 1986 | May 17 | 199 | 236 |
| 1985 | May 18 | 182 | N/A |
| 1984 | May 19 | 201 | N/A |
Total Cumulative refers to the total species seen by all teams during a given year.