Year % of total population 1960 6.36736393537735 1961 6.13905708195111 1962 5.92062530753582 1963 5.72710515935731 1964 5.5703323081406 1965 5.44762533329611 1966 5.36408184103965 1967 5.3187139796355 1968 5.29202989575931 1969 5.26251862739094 1970 5.22315792684221 1971 5.1762805700534 1972 5.11650753555589 1973 5.05337581691746 1974 5.00807202038499 1975 4.97806997927755 1976 4.96211659997143 1977 4.96109589261438 1978 4.95735095651547 1979 4.92790008834649 1980 4.86438183261907 1981 4.7687974705821 1982 4.6410018121774 1983 4.4995262308024 1984 4.42102598500131 1985 4.42347032849785 1986 4.45171906453892 1987 4.49901212787632 1988 4.58685492214579 1989 4.69094190856919 1990 4.75184618682268 1991 4.79775561287531 1992 4.87055900687352 1993 4.94883845370304 1994 5.02920560167534 1995 5.094870917942 1996 5.12173248746139 1997 5.12427649414801 1998 5.11033203708248 1999 5.0808571830886 2000 5.06030983254518 2001 5.07593782043921 2002 5.12186914463663 2003 5.17714031522309 2004 5.21683693333126 2005 5.21745769662073 2006 5.16465797626546 2007 5.02989225868454 2008 4.79512816123725 2009 4.49736197344519 2010 4.21247301584639 2011 4.00607996400794 2012 3.89225722065561 2013 3.83564469994195 2014 3.8202967021202 2015 3.84582840129397 2016 3.89556916331342 2017 3.96296645110921 2018 4.04861770183938 2019 4.15722392930784 2020 4.26798253164187 2021 4.38525196340818 2022 4.54212221083901 2023 4.74545671177322