tba
U.K. (United Kingdom) 1989:
tba
U.K. (United Kingdom) 1990:
tba
U.K. (United Kingdom) 1991:
tba
U.K. (United Kingdom) 1992:
tba
U.K. (United Kingdom) 1993:
54500
U.K. (United Kingdom) 1994:
61000
U.K. (United Kingdom) 1995:
70000
U.K. (United Kingdom) 1996:
70000
U.K. (United Kingdom) 1997:
48800
U.K. (United Kingdom) 1998:
tba
U.K. (United Kingdom) 1999: