Year	% of total primary
1976	37.6616706848145
1977	37.3768997192383
1999	36.3664512634277
2000	37.2343482971191
2001	39.1377906799316
2002	38.3347282409668
2004	32.9961318969727
2005	34.135799407959
2006	34.6142692565918
2007	35.4830017089844
2008	36.1616706848145
2011	36.6624794006348
2012	37.5154991149902
2013	38.3037986755371
2018	43.7543601989746
2019	45.7673187255859
2020	46.7357711791992
2021	45.7701110839844
2022	48.8459815979004