Year % of total population 1960 4.510485737071 1961 4.38769644837567 1962 4.2591734917015 1963 4.12865149445872 1964 4.00892317786674 1965 3.91545296771342 1966 3.84287324458525 1967 3.77253732266376 1968 3.70016161979253 1969 3.63080657689968 1970 3.56504399539697 1971 3.50333449078802 1972 3.44249988573109 1973 3.36011987011193 1974 3.24949551399759 1975 3.13001575370723 1976 3.01705700174355 1977 2.91521182781527 1978 2.82353178570514 1979 2.7422000719226 1980 2.67306731651995 1981 2.61581280684495 1982 2.56818570876909 1983 2.53267620674426 1984 2.52713738940741 1985 2.5505844034674 1986 2.58918854838262 1987 2.64242327878537 1988 2.70547659928411 1989 2.77273175760298 1990 2.8421638699046 1991 2.91402222631151 1992 2.98816341402313 1993 3.06388194684255 1994 3.14146091953627 1995 3.22232135933961 1996 3.30648965112826 1997 3.39212117954559 1998 3.47778235186118 1999 3.56302038869924 2000 3.63377557572665 2001 3.69082828460499 2002 3.73230032749181 2003 3.7508656749432 2004 3.77511455918067 2005 3.81135720435095 2006 3.82646678729652 2007 3.85746519598618 2008 3.89684589251715 2009 3.92703615347401 2010 3.96035882693859 2011 4.24695206889575 2012 4.55508345541865 2013 4.55586351782165 2014 4.58472154711137 2015 4.65147882791916 2016 4.71747459009557 2017 4.76206565064791 2018 4.77897333242973 2019 4.78723226116015 2020 4.80500882033537 2021 4.82233321658486 2022 4.86495758212926 2023 4.96996539683885