Year	% of total
1990	84.74015854277647
1991	84.60799823189615
1992	84.99540004435849
1993	84.84505150846012
1994	85.14813302118027
1995	85.2535913007577
1996	85.0581400051618
1997	84.23812121050018
1998	83.87046863283979
1999	83.67944403422105
2000	82.93841342529703
2001	82.94079380253939
2002	83.0320113858362
2003	82.75211710084511
2004	82.39786049564863
2005	82.16009475866375
2006	81.2717273657872
2007	81.39917853288935
2008	80.79111844796802