Year Percent 1950 16.88998 1955 17.8852 1960 15.76587 1965 14.44131 1970 16.33227 1975 17.70932 1980 20.88697 1985 19.57773 1990 18.31847 1995 19.72722 2000 22.08769 2005 26.66616 2010 27.54739 2015 27.0495 2020 25.68008 2025 26.28262 2030 29.34017 2035 31.53529 2040 30.38677 2045 27.3408 2050 24.40918 2055 23.1812 2060 24.09217 2065 24.75466 2070 23.87279 2075 22.37712 2080 21.64336 2085 21.83425 2090 22.47049 2095 22.85489 2100 22.60392