Year	% of total
1990	82.73003869350579
1991	82.66595088259942
1992	82.36898241555149
1993	82.05850786286214
1994	82.03420108352009
1995	80.66336385702992
1996	79.46247944365582
1997	79.9852194329205
1998	80.06645121927333
1999	79.53992196838091
2000	78.13462985578708
2001	78.36045557458696
2002	79.27098299203277
2003	78.29046796319008
2004	77.5026687674511
2005	76.9503451654416
2006	76.98373972742885
2007	76.29442099987558
2008	78.2217648646375