Year	Percent
1960-01-01	1.67659912611287
1961-01-01	3.98562050634916
1962-01-01	2.87088531460981
1963-01-01	5.93950905922400
1964-01-01	4.03420453764313
1965-01-01	3.06907066175741
1966-01-01	5.45372692773337
1967-01-01	3.81813815731005
1968-01-01	4.31765612971038
1969-01-01	6.32668144851306
1970-01-01	5.12998748779380
1971-01-01	8.38402539015845
1972-01-01	7.88189360668075
1973-01-01	13.01176204502210
1974-01-01	23.32135426528190
1975-01-01	15.36298568512630
1976-01-01	10.67139375137380
1977-01-01	13.01405517975560
1978-01-01	11.65007263577890
1979-01-01	10.26625622800330
1980-01-01	13.04898405559740
1981-01-01	16.38747454182290
1982-01-01	16.25796959288460
1983-01-01	48.43387471031220
1984-01-01	31.23023908494750
1985-01-01	27.98321602596000
1986-01-01	23.03022611437470
1987-01-01	29.50399724927190
1988-01-01	58.21628654116770
1989-01-01	75.64819010220010
1990-01-01	48.51911299645570
1991-01-01	48.80382775119620
1992-01-01	54.34083601286180
1993-01-01	44.99999999999990
1994-01-01	27.44252873563210
1995-01-01	22.88613303269450
1996-01-01	24.37308868501560
1997-01-01	30.64298008359870
1998-01-01	36.09843316237830
1999-01-01	52.24235090751880
2000-01-01	96.09411369308370
2001-01-01	37.67802094214150
2002-01-01	12.48401857210180
2003-01-01	7.92941000523416
2004-01-01	2.74218132941644
2005-01-01	2.40776978315688
2006-01-01	3.03487429304912
2007-01-01	2.27630123486886
2008-01-01	8.40082543392809
2009-01-01	5.15792399974339
2010-01-01	3.55612380577120
2011-01-01	4.47592160246182
2012-01-01	5.10065348011050
2013-01-01	2.73863175715957
2014-01-01	3.57925112628889
2015-01-01	3.96808469061811
2016-01-01	1.72826463324536
2017-01-01	0.41733558866681