Year % of total population 1960 3.27638442378167 1961 3.25854421270248 1962 3.25230360250838 1963 3.25055077637862 1964 3.24314599425785 1965 3.22781900298111 1966 3.20688132760967 1967 3.18059318236551 1968 3.15038379981258 1969 3.11946000952846 1970 3.08954837170241 1971 3.0591091233954 1972 3.02704260677489 1973 2.9932735738777 1974 2.96087455617887 1975 2.98521087339489 1976 3.05897120499074 1977 3.12572469095836 1978 3.18209267321021 1979 3.22207180341802 1980 3.2469249521571 1981 3.2580360607038 1982 3.25776892241773 1983 3.25490609769552 1984 3.26073732739438 1985 3.27900106046617 1986 3.30850994919243 1987 3.34914892323224 1988 3.34062735415821 1989 3.28261400249162 1990 3.23054503314115 1991 3.18406931071723 1992 3.14074113711273 1993 3.10135431435567 1994 3.06950337647671 1995 3.04609724193794 1996 3.03002593720674 1997 3.02028999471364 1998 3.01142721363131 1999 3.00368282472888 2000 2.99901978825924 2001 2.99707737572631 2002 2.99997542702664 2003 3.00545114571118 2004 3.01083923795879 2005 3.01653898223214 2006 3.02467980168362 2007 3.03693171851919 2008 3.05494090987693 2009 3.08169237502193 2010 3.11929482338192 2011 3.16825581244985 2012 3.23251424971878 2013 3.31426032711664 2014 3.40905710892487 2015 3.51737378605026 2016 3.63572415538965 2017 3.75704722275488 2018 3.88090800941503 2019 4.00678634004058 2020 4.117187885154 2021 4.19788379365142 2022 4.27078022089725 2023 4.37977956536457