Year % of total population 1960 39.66805183831727 1961 39.72892097224365 1962 39.87102078554019 1963 40.19289342160057 1964 40.42685356221461 1965 40.48241396076059 1966 40.4692884874856 1967 40.346176409498646 1968 40.201503071453025 1969 40.07900161193742 1970 39.91033472146548 1971 39.7427323258188 1972 39.525330660153884 1973 39.30332055601974 1974 39.1683552018273 1975 39.049770273145455 1976 38.91838461330149 1977 38.61180869313716 1978 38.02738113909742 1979 37.43519328968075 1980 36.94705597434092 1981 36.50978501494716 1982 36.15602509577483 1983 35.768425538522486 1984 35.32465409216882 1985 34.91006664827789 1986 34.53780766118303 1987 34.23137487553898 1988 33.94243772648558 1989 33.674453190418795 1990 33.46272198767578 1991 33.24315818602723 1992 32.991581719185234 1993 32.729662141029955 1994 32.4190090026506 1995 32.049347749182104 1996 31.626944333532162 1997 31.138746470078324 1998 30.636970916828503 1999 30.14122734997633 2000 29.628373556140424 2001 29.085618708635995 2002 28.50301544691717 2003 27.931566310479475 2004 27.38419357457048 2005 26.838955670012265 2006 26.361200485612933 2007 25.983147927445835 2008 25.666393528737995 2009 25.394013385100546 2010 25.14636279199031 2011 24.923102654861914 2012 24.73796790190785 2013 24.574513971477764 2014 24.416772737266424 2015 24.24540205958854 2016 24.065538215933934 2017 23.89674078452105 2018 23.70619761431167 2019 23.47641795668588 2020 23.21086840460376 2021 22.92480417649028 2022 22.632297641967853 2023 22.294291217421346