Year % of total primary 1970 6.891930103302 1971 6.99519014358521 1972 7.13095998764038 1973 7.14278984069824 1974 7.37158012390137 1975 7.42534017562866 1976 7.41039991378784 1977 7.42082023620605 1978 7.41763019561768 1979 7.40883016586304 1980 7.39840984344482 1981 7.34322023391724 1982 7.20663976669312 1983 7.07153987884521 1984 6.82334995269775 1985 6.6641001701355 1986 6.6287899017334 1987 6.55764007568359 1988 6.37411022186279 1989 6.34944009780884 1990 6.26051998138428 1991 6.16882991790771 1992 6.07145977020264 1993 6.0786600112915 1994 6.18818998336792 1995 6.15898990631104 1996 6.33539009094238 1997 6.2997899055481 1998 6.28539991378784 1999 6.18215990066528 2000 6.22805976867676 2001 6.27728986740112 2002 6.32699012756348 2003 6.37540006637573 2004 6.29113006591797 2005 6.4727897644043 2006 6.53353977203369 2007 6.57804012298584 2008 6.60504007339478 2009 6.63813018798828 2010 6.59677982330322 2011 6.58064985275269 2012 6.85442018508911 2013 7.34416007995605 2014 7.6775598526001 2015 8.14151000976562 2016 8.4712495803833 2017 8.82277965545654 2018 9.22387981414795 2019 9.59387016296387 2020 9.91454982757568 2021 9.96988010406494 2022 9.98390007019043