Year % of total population 1960 3.55676487234682 1961 3.57341630431472 1962 3.59329993850845 1963 3.61277070399558 1964 3.62727790651035 1965 3.63550153737849 1966 3.6379064587794 1967 3.63459781336638 1968 3.62718590595689 1969 3.6167689140436 1970 3.60339143565503 1971 3.58738042557092 1972 3.56806218919876 1973 3.5464798081809 1974 3.52453474211366 1975 3.49903334565178 1976 3.46912907150037 1977 3.43925895339974 1978 3.40829678452524 1979 3.37061718128965 1980 3.32916770534031 1981 3.29348744212901 1982 3.28423137372756 1983 3.31049944655085 1984 3.3537830471947 1985 3.39271035019923 1986 3.41652614780341 1987 3.42968783553728 1988 3.42501073963226 1989 3.39167803744131 1990 3.35037425039877 1991 3.31866295344123 1992 3.30269286517268 1993 3.29398481517003 1994 3.27481375180507 1995 3.24826633322503 1996 3.21837182839563 1997 3.18298567687749 1998 3.13933513813398 1999 3.09184763673985 2000 3.04186622336098 2001 2.99961494741558 2002 2.97390577090609 2003 2.94882473477236 2004 2.91281865723552 2005 2.87010947117475 2006 2.82529211730715 2007 2.77968576168536 2008 2.7321732936571 2009 2.68235480375206 2010 2.63675210978926 2011 2.60104454065864 2012 2.57689137011745 2013 2.56255791008678 2014 2.55469238117185 2015 2.55213563895011 2016 2.55756726636254 2017 2.57099532136453 2018 2.59026638549607 2019 2.61702567840046 2020 2.64763930388655 2021 2.67778778115654 2022 2.72087878515831 2023 2.77927199682849