Year	Percent
1965	68.87721
1966	41.24714
1967	38.85226
1968	51.16326
1969	54.30249
1970	34.33337
1971	39.02131
1972	28.77173
1973	39.17839
1974	54.00543
1975	44.04994
1976	39.81396
1977	40.94988
1978	61.83867
1979	65.96233
1980	48.26022
1981	75.70741
1982	42.11377
1983	53.8592
1984	63.04294
1985	49.81649
1986	97.12136
1987	82.44563
1988	67.34002
1989	81.88663
1990	75.23831
1991	58.86739
1992	55.57604
1993	45.65418
1994	73.64345
1995	67.39736
1996	53.37585
1997	44.33932
1998	41.17182
1999	36.93555
2000	32.12191
2001	25.45454
2002	27.4944
2003	21.84337
2004	44.77557
2005	25.92564
2006	33.15255
2007	25.1173
2008	24.11245
2009	30.91046
2010	28.91658
2011	28.18987
2012	24.73723
2013	21.84215
2014	21.63833
2015	18.93371
2016	15.14245
2017	14.5071
2018	13.23749
2019	19.22288
2020	18.43587
2021	12.96162