6800
U.K. (United Kingdom) 1996:
13500
U.K. (United Kingdom) 1997:
10000
U.K. (United Kingdom) 1998:
10000
U.K. (United Kingdom) 1999:
10000
U.K. (United Kingdom) 2000:
10700
U.K. (United Kingdom) 2001:
6900
U.K. (United Kingdom) 2002:
5600
U.K. (United Kingdom) 2003:
4500
U.K. (United Kingdom) 2004:
4000
U.K. (United Kingdom) 2005:
3000
U.K. (United Kingdom) 2006: