Year % of total population 1960 33.733019210741 1961 33.887704307462 1962 33.9197023790505 1963 33.8354601183369 1964 33.6269423376176 1965 33.2920738460257 1966 32.824129563195 1967 32.2392266777081 1968 31.595570088909 1969 30.9226096233661 1970 30.1367715350762 1971 29.3019647279765 1972 28.5186323185248 1973 27.7313548036046 1974 26.94309839477 1975 26.174762446398 1976 25.4318141821208 1977 24.7169249347948 1978 24.0162691253834 1979 23.3475207443506 1980 22.7695381224889 1981 22.3292278082744 1982 22.0184158188843 1983 21.7771328786092 1984 21.5470089524578 1985 21.2955916926152 1986 21.0620885507625 1987 20.9105167576737 1988 20.8194766941448 1989 20.7522894791687 1990 20.7096852467501 1991 20.6975159571342 1992 20.6959958448746 1993 20.655386175464 1994 20.5502338180506 1995 20.3963700547527 1996 20.2105832870878 1997 19.9959779474126 1998 19.7518548133589 1999 19.4772313711836 2000 19.1803802148155 2001 18.8801514058626 2002 18.5939355601062 2003 18.3133577592273 2004 18.0129503413461 2005 17.6890127848608 2006 17.3790286920821 2007 17.1221790968561 2008 16.9139866334585 2009 16.7285836301852 2010 16.5573556544119 2011 16.417837372268 2012 16.325320924896 2013 16.2713032692422 2014 16.2428037615894 2015 16.2364324473724 2016 16.2256366948544 2017 16.1748393949584 2018 16.0869478578438 2019 15.9841708131805 2020 15.8683623523158 2021 15.7333681352269 2022 15.5770948741347 2023 15.4052205816818