Year % of total population 1960 9.03027409817042 1961 9.25967605232376 1962 9.4973053827319 1963 9.7580986910372 1964 10.0566249926403 1965 10.3510222290461 1966 10.6460865688972 1967 10.9342899088174 1968 11.1770619048298 1969 11.3717657831281 1970 11.547990638432 1971 11.7374646393561 1972 11.9699512856647 1973 12.2263624298467 1974 12.4796052227077 1975 12.7044054570446 1976 12.8910138891508 1977 13.0886478590911 1978 13.2716391454479 1979 13.4255525105435 1980 13.406393443527 1981 13.1161814576307 1982 12.7394222647392 1983 12.3593226358435 1984 12.2053389281911 1985 12.3339019228798 1986 12.5323108097149 1987 12.7601675105315 1988 12.9970528351996 1989 13.1877007907679 1990 13.3670865800317 1991 13.5635018376834 1992 13.7193269026733 1993 13.8651848691477 1994 14.0295504907259 1995 14.2194044554028 1996 14.3948971056485 1997 14.5512005381958 1998 14.7246558109317 1999 14.8717881546659 2000 15.0023157099231 2001 15.1211564602123 2002 15.2263831895102 2003 15.3343051268118 2004 15.4494591976764 2005 15.5900235721843 2006 15.7446968237495 2007 15.9318013839321 2008 16.1344479129566 2009 16.3623669073119 2010 16.5612494461453 2011 16.7560537671912 2012 17.0364832056675 2013 17.3641899737732 2014 17.7269259186933 2015 18.0962513533286 2016 18.4745307602176 2017 18.8056808187934 2018 19.1435511641222 2019 19.6125829690153 2020 20.0974558160559 2021 20.4198836102052 2022 20.0106949645127 2023 19.7461875404862