Year	% of total
1990	94.02728621097852
1991	93.9834202620528
1992	93.96539160648015
1993	93.90458837540915
1994	93.10518335602544
1995	92.49571901013896
1996	91.83784801602275
1997	91.23951631578343
1998	90.62743139493544
1999	90.07864301868648
2000	89.21411060685953
2001	88.96234379545727
2002	88.35410951906938
2003	88.26832427590452
2004	88.19187958170761
2005	88.32991455031956
2006	88.29401573266281
2007	88.15954876048283
2008	88.0528889679678