Year	Percent
1978	18.44562
1979	16.07442
1980	17.74891
1981	13.49972
1982	13.02692
1983	10.8183
1984	12.77348
1985	11.61884
1986	16.64828
1987	6.86024
1988	9.37234
1989	7.5432
1990	6.39439
1991	11.98357
1992	16.30995
1993	5.87472
1994	10.29464
1995	15.31556
1996	10.62867
1997	13.09794
1998	14.05629
1999	18.81466
2000	9.95065
2001	16.23631
2002	15.33746
2003	11.03252
2004	5.59413
2005	3.44227