Year % of total population 1960 41.2936637608129 1961 41.3210414663439 1962 41.2500258715549 1963 41.1369712690636 1964 41.0577407188999 1965 40.9752035844492 1966 40.8305859573619 1967 40.656315335708 1968 40.4594526039277 1969 40.2239106898661 1970 39.9423865276687 1971 39.6110197108154 1972 39.2362179842327 1973 38.8095942994154 1974 38.3276957486938 1975 37.8398768019041 1976 37.4019799901798 1977 37.0133665370617 1978 36.6661925017354 1979 36.3686393281049 1980 36.1016885807207 1981 35.8491966336025 1982 35.5458695401112 1983 35.1599879745383 1984 34.7466597658761 1985 34.3167444034546 1986 33.8633790487128 1987 33.3850462004338 1988 32.8879883143508 1989 32.4220683401807 1990 31.9786267152458 1991 31.5141221765114 1992 31.0349873474116 1993 30.5004403355251 1994 29.8882356977759 1995 29.2584832215633 1996 28.6355670998279 1997 28.0591150066893 1998 27.5671479094581 1999 27.1363301232006 2000 26.7918624956867 2001 26.5288638775071 2002 26.3183310360609 2003 26.163259110675 2004 26.0345679374663 2005 25.923273036423 2006 25.8275876055939 2007 25.7341272543935 2008 25.657910514789 2009 25.5959234226389 2010 25.5182080316926 2011 25.4233483467018 2012 25.3398950866167 2013 25.2612010743168 2014 25.1514433725872 2015 24.9875876995491 2016 24.7700403080554 2017 24.5163619667024 2018 24.2365751636531 2019 23.9286831426114 2020 23.5872127477129 2021 23.2146568660107 2022 22.8178104183359 2023 22.4145832894658