Year	% of total
1960	100
1961	100
1962	100
1963	100
1964	100
1965	100
1966	95.75070821529744
1967	91.3793103448276
1968	90.64449064449065
1969	90.68541300527241
1970	91.89189189189189
1971	90.78590785907859
1972	90.02433090024331
1973	89.71428571428571
1974	91.14315139031926
1975	100
1976	100
1977	100
1978	100
1979	100
1980	89.56982911019445
1981	86.61740558292283
1982	90.99639855942377
1983	93.40909090909092
1984	95.04748982360921
1985	95.39539539539538
1986	93.54640442532268
1987	95.75178997613367
1988	96.19695756605284
1989	97.07401032702238
1990	176.58431734317344
1991	154.56602150537634
1992	138.86942238267147
1993	172.20033783783782
1994	133.8633009708738
1995	184.9247852760736
1996	167.0942268041237
1997	117.12964509394573
1998	102.49378881987576
1999	53.11394618834081
2000	63.955260663507104
2001	76.32749201277956
2002	67.1900156739812
2003	54.04374757281553
2004	80.30865313653138
2005	71.6990017211704
2006	65.39374777975134
2007	65.80778378378378
2008	55.92751572327044
2009	46.069392917369306
2010	48.69681672025724
2011	55.9538898163606
2012	64.37002534854246
2013	68.3553073286052
2014	66.54622767857144
2015	58.07361924686192
2016	38.20447424892704