Year Percent 1950 29.69121 1955 29.92112 1960 29.77378 1965 28.53643 1970 26.67265 1975 26.24965 1980 27.23521 1985 29.13472 1990 31.72441 1995 33.5972 2000 34.70023 2005 34.04634 2010 33.46416 2015 32.4319 2020 31.61804 2025 31.09546 2030 30.63629 2035 30.52869 2040 30.18023 2045 29.46751 2050 28.86401 2055 28.05555 2060 27.49366 2065 27.06493 2070 26.65561 2075 26.19261 2080 25.70051 2085 25.24981 2090 24.88358 2095 24.58711 2100 24.32272