Year Percent 1950 21.68419 1955 21.5752 1960 21.70115 1965 20.0615 1970 18.45585 1975 17.56671 1980 16.66571 1985 17.00999 1990 17.53473 1995 19.70595 2000 20.47684 2005 20.29238 2010 20.18628 2015 21.00584 2020 21.35145 2025 20.59039 2030 19.57459 2035 19.25091 2040 19.73638 2045 21.03966 2050 22.50483 2055 23.26027 2060 23.39583 2065 23.2619 2070 23.10613 2075 23.16484 2080 23.39641 2085 23.58482 2090 23.60689 2095 23.48651 2100 23.32169