Year	Percent
1971	0.5002
1973	0.05356
1974	60.56821
1975	123.7112
1976	135.99577
1977	171.70966
1978	186.4149
1979	202.9346
1980	186.31759
1981	160.95664
1982	135.17546
1983	170.03049
1984	104.11452
1985	111.83563
1986	223.62485
1987	181.44085
1988	137.14223
1989	138.28834
1990	173.06411
1991	141.57486
1992	97.96553
1993	129.3241
1994	339.9086
1995	207.637
1996	289.98657
1997	193.21882
1998	409.10994
1999	150.7086
2000	186.06784
2001	151.18083
2002	193.27157
2003	335.21203
2004	165.80706
2005	103.13955
2006	149.03273
2007	143.91466
2008	122.24042
2009	166.6084
2010	140.73535
2011	110.40857
2012	121.19811
2013	139.77105
2014	91.54276
2015	112.19375
2016	213.39051
2017	93.27802
2018	59.16025
2019	38.58157
2020	61.46078