Year	% of total
1990	71.85867607125044
1991	73.9299443297148
1992	72.19057986409611
1993	70.58867140839789
1994	69.10915010788783
1995	67.1376109988292
1996	66.12399363499188
1997	67.61389876647148
1998	68.37961972453533
1999	68.66852056825329
2000	65.56074054946978
2001	66.30577797963235
2002	68.21537341996053
2003	66.37091679992751
2004	65.31040851793075
2005	64.62908373577486
2006	65.9561161147088
2007	65.9669947468958
2008	70.09845706680467