Year % of total population 1960 4.27911098459625 1961 4.26703601200151 1962 4.25605054345126 1963 4.24653865894752 1964 4.23718254227838 1965 4.22671370615318 1966 4.21609662449977 1967 4.20546487510145 1968 4.19264008803709 1969 4.17263909649787 1970 4.14437997660602 1971 4.11038681072594 1972 4.07070858470416 1973 4.02924896777619 1974 3.98910468944189 1975 3.95056193362435 1976 3.92359172557866 1977 3.90569787449311 1978 3.92532878708906 1979 3.94794293318737 1980 3.95509806161619 1981 3.98832886787284 1982 3.99424974428667 1983 3.96356351918597 1984 3.92808060682047 1985 3.88617694324854 1986 3.83483179586335 1987 3.77607244704854 1988 3.7058683768934 1989 3.54495485493801 1990 3.41056426865818 1991 3.37227512808902 1992 3.34021579175295 1993 3.30807780587872 1994 3.27533977691923 1995 3.24411093887673 1996 3.21671884133155 1997 3.19242612692102 1998 3.16918142369062 1999 3.14846811029212 2000 3.13389671278917 2001 3.12666568807142 2002 3.12762605737282 2003 3.13959043032225 2004 3.16151006068612 2005 3.19056583106836 2006 3.22613283880964 2007 3.26735161446121 2008 3.31328396658117 2009 3.36282432657557 2010 3.41597235801675 2011 3.47146715076696 2012 3.52692309466798 2013 3.58102254015632 2014 3.63860738359011 2015 3.70231970505155 2016 3.76828392770445 2017 3.8355768696024 2018 3.90459165296472 2019 3.97587389586023 2020 4.03264556076137 2021 4.02808054303489 2022 3.969010669017 2023 3.93318874482945