Year Percent 1950 29.69226 1955 27.00425 1960 25.81709 1965 25.35586 1970 24.08528 1975 25.2707 1980 25.12514 1985 24.31708 1990 25.16932 1995 26.62755 2000 29.04971 2005 30.48291 2010 30.29046 2015 30.24772 2020 30.11947 2025 29.99999 2030 30.12011 2035 30.48557 2040 30.68121 2045 30.86977 2050 30.85142 2055 30.65976 2060 30.52952 2065 30.43178 2070 30.29598 2075 30.08302 2080 29.78414 2085 29.45465 2090 29.10543 2095 28.74344 2100 28.36049