Year	Percent
1960	0.03235
1961	0.03111
1963	0.02255
1965	111.01547
1966	97.72331
1967	101.42443
1968	104.58098
1969	74.23201
1970	54.97884
1971	47.10651
1972	81.14437
1973	96.9549
1974	102.81397
1975	111.9837
1976	83.84244
1977	70.92201
1978	66.05211
1979	52.27411
1980	49.57459
1981	46.92847
1982	40.18524
1983	42.93551
1984	45.80554
1985	52.58775
1986	49.06052
1987	48.43214
1988	36.60924
1989	39.59232
1990	47.04046
1991	33.17885
1992	42.46553
1993	32.24742
1994	25.40918
1995	35.22912
1996	32.34004
1997	32.58198
1998	52.87639
1999	37.32166
2000	35.67035
2001	29.12382
2002	32.02991
2003	31.63071
2004	33.37437