tba
U.K. (United Kingdom) 1986:
tba
U.K. (United Kingdom) 1987:
tba
U.K. (United Kingdom) 1988:
tba
U.K. (United Kingdom) 1989:
35000
U.K. (United Kingdom) 1990:
18500
U.K. (United Kingdom) 1991:
13600
U.K. (United Kingdom) 1992:
24100
U.K. (United Kingdom) 1993:
14000
U.K. (United Kingdom) 1994:
tba
U.K. (United Kingdom) 1995:
tba
U.K. (United Kingdom) 1996: