Year	% of total primary
1970	8.829270362854
1971	9.25325012207031
1972	9.10076999664307
1973	8.95773983001709
1974	8.51729965209961
1975	7.98994016647339
1976	7.90422010421753
1977	7.899010181427
1978	7.90778017044067
1979	7.89228010177612
1980	7.91388988494873
1981	7.97713994979858
1982	8.08640956878662
1983	8.18496990203857
1984	8.27149963378906
1985	8.2952299118042
1986	8.32007026672363
1987	8.35536003112793
1988	8.49450016021729
1989	8.6192798614502
1990	8.73987007141113
1991	8.83333969116211
1992	8.99332046508789
1993	9.1325798034668
1994	9.27381992340088
1995	9.41594982147217
1996	9.52624034881592
1997	9.63243961334229
1998	9.76451969146729
1999	9.95660018920898
2000	10.1145296096802
2001	10.3789901733398
2002	10.4573202133179
2003	11.2281999588013
2004	11.6510896682739
2005	12.3957796096802
2006	12.9349403381348
2007	13.5964803695679
2008	14.0326099395752
2009	14.701470375061
2010	15.266489982605
2011	15.963020324707
2012	16.4860305786133
2013	16.9266395568848
2014	17.3147296905518
2015	17.4468002319336
2016	17.3638095855713
2017	17.8085803985596
2018	19.1407909393311
2019	19.0922298431396
2020	19.3764896392822
2021	19.3138008117676
2022	19.6417694091797