Year % of total population 1960 11.096595823620259 1961 11.421260632213507 1962 11.755180648883405 1963 12.1043999071502 1964 12.492398343148068 1965 12.88764390525009 1966 13.291748895234099 1967 13.702247092272604 1968 14.119931916379347 1969 14.543729810469294 1970 14.97954610807492 1971 15.342423878857137 1972 15.395043450669219 1973 15.4494628080844 1974 15.479788286266377 1975 15.515592338793075 1976 15.557833981463324 1977 15.606974080850897 1978 15.67793197091043 1979 15.782324734600978 1980 15.883890971144387 1981 15.971055364885059 1982 16.072311224872603 1983 16.19297496798815 1984 16.33873551810164 1985 16.50006351258054 1986 16.671058305298235 1987 16.85084954495323 1988 17.032071328351957 1989 17.20450704416354 1990 17.379831686306417 1991 17.561988579916896 1992 17.754607230078253 1993 17.95824718685114 1994 18.177572720236267 1995 18.31863630308715 1996 18.064263689297068 1997 17.844582944066968 1998 17.65047385171569 1999 17.474125117478085 2000 17.310200494922924 2001 17.16365311421817 2002 17.03221102999312 2003 16.9113754451855 2004 16.796742355450192 2005 16.686997839285837 2006 16.789018648196112 2007 16.88720351289614 2008 16.98177695761272 2009 17.071644925284705 2010 16.93937941853233 2011 16.806833695887946 2012 16.675601643416655 2013 16.546679001251597 2014 16.42098895158968 2015 16.297992029337323 2016 16.177554902895263 2017 16.059607451980796 2018 15.944702508264694 2019 15.838595998393739 2020 15.744738483946241 2021 15.660838415657743 2022 15.587692807199133 2023 15.533094626833051