Year % of total population 1960 19.752758725788265 1961 19.76999988407388 1962 19.783979039550374 1963 19.790102622010995 1964 19.795866664405718 1965 19.81059914465809 1966 19.840433998141048 1967 19.883524678100077 1968 19.937356481408926 1969 19.99698265855337 1970 20.062728617048094 1971 19.9069458144507 1972 19.732805891492784 1973 19.59606251890207 1974 19.49200609150753 1975 19.419894569282782 1976 19.379936926496807 1977 19.371001182108618 1978 19.391672300453465 1979 19.43828313696436 1980 19.506128335637484 1981 19.56402763449682 1982 19.62988932950404 1983 19.6783123114407 1984 19.71800019849906 1985 19.753525553736885 1986 19.78506137474745 1987 19.808480949286864 1988 19.82026070284083 1989 19.827177003695294 1990 19.84044875727885 1991 19.811043912288177 1992 19.747132444118687 1993 19.70722264336265 1994 19.687749116922273 1995 19.680849749462396 1996 19.679977188790218 1997 19.681347618308532 1998 19.682070242976145 1999 19.681729893169834 2000 19.682821331681822 2001 19.688113799223224 2002 19.697931549282988 2003 19.60351335276386 2004 19.490536283504024 2005 19.387559115975527 2006 19.295900851018104 2007 19.213670909033958 2008 19.136009770313045 2009 19.059095459305155 2010 18.981300690665368 2011 18.90206050071203 2012 18.819271589993715 2013 18.7342065978606 2014 18.703231002117363 2015 18.727661828232257 2016 18.76168884321406 2017 18.808484700396644 2018 18.859657330827268 2019 18.89614080857692 2020 18.940626499354288 2021 19.036915268969434 2022 19.137124938381803 2023 19.196389210402405