Year Percent 1950 21.88185 1955 22.54506 1960 20.25995 1965 20.99248 1970 21.73781 1975 22.62675 1980 24.76383 1985 23.65385 1990 22.96184 1995 24.01964 2000 25.21368 2005 25.81495 2010 28.07633 2015 28.715 2020 29.69814 2025 30.73762 2030 30.51819 2035 28.96378 2040 27.0762 2045 26.49283 2050 25.14449 2055 24.97861 2060 24.95993 2065 24.86353 2070 24.35449 2075 24.11372 2080 23.99174 2085 23.95128 2090 23.93829 2095 23.85852 2100 23.66043