Year Percent 1950 28.14909 1955 26.38199 1960 25.13786 1965 24.80617 1970 25.47335 1975 28.84997 1980 33.22381 1985 33.38285 1990 33.38442 1995 38.61103 2000 37.81155 2005 38.50506 2010 49.44202 2015 55.4217 2020 56.90417 2025 50.0861 2030 42.8446 2035 37.00863 2040 34.92781 2045 34.0698 2050 30.60442 2055 26.96035 2060 24.12397 2065 22.82616 2070 22.61065 2075 22.67928 2080 22.64678 2085 22.37384 2090 22.0166 2095 21.80799 2100 21.84162