| Year | Distance |
|---|---|
| 1988 | 2,781 |
| 1989 | 3,490 |
| 1990 | 4,165 |
| 1991 | 2,741 |
| 1992 | 3,650 |
| 1993 | 3,564 |
| 1994 | 4,845 |
| 1995 | 4,003 |
| 1996 | 3,427 |
| 1997 | 3,258 |
| 1998 | 3,419 |
| 1999 | 3,288 |
| 2000 | 3,645 |
| 2001 | 3,455 |
| 2002 | 3,134 |
| 2003 | 3,071 |
| 2004 | 3,107 |
| 2005 | 3,545 |
| 2006 | 4,994 |
| 2007 | 4,914 |
| 2008 | 3,321 |
| 2009 | 2,903 |
| 2010 | 4,474 |
| 2011 | 4,354 |
| 2012 | 3,555 |
| 2013 | 4,299 |
| 2014 | 4,922 |
| 2015 | 1,821 |
| 2016 | 1,839 |
| 2017 | 984 |
| Total | 104,968 |