Year % of total population 1960 21.76843330762837 1961 22.2588696185424 1962 22.83730810928155 1963 23.483538481949378 1964 24.15110918615266 1965 24.809372921499083 1966 25.417978973143907 1967 26.021558049619024 1968 26.684334837968986 1969 27.439732791170492 1970 28.25648604097486 1971 28.915101240669838 1972 29.23378051145801 1973 29.6125045721365 1974 30.02264444340797 1975 30.265324614125994 1976 30.32375396570583 1977 30.457543063694935 1978 30.59402485206988 1979 30.746456578781178 1980 30.982229202888668 1981 31.126591190572857 1982 30.981816970874853 1983 30.848431650757156 1984 30.741361917039356 1985 30.6682101406239 1986 30.61290051692484 1987 30.556591882782975 1988 30.49166268389615 1989 30.378498513999407 1990 30.104046449118506 1991 29.80831162856094 1992 29.69030569202354 1993 29.624455626282515 1994 29.58479098389582 1995 29.555072720495527 1996 29.533377950380817 1997 29.495869108892297 1998 29.440617045328725 1999 29.435689423732203 2000 29.423380463543307 2001 29.342278293064382 2002 29.217790974921897 2003 29.131072549864705 2004 29.042045191385483 2005 28.94006669874002 2006 28.836375792374152 2007 28.746153427718017 2008 28.65312834874593 2009 28.56115192765078 2010 28.507659283174576 2011 28.53313659133685 2012 28.671035275564687 2013 28.862764245941097 2014 29.03864368712424 2015 29.213466220825048 2016 29.31802618993685 2017 29.35885859540764 2018 29.40123631285614 2019 29.418718245124648 2020 29.474466703537537 2021 29.834357487747187 2022 30.24652824098854 2023 30.444678971113166