Year Percent 1950 29.51634 1955 28.39474 1960 27.43264 1965 26.18779 1970 24.95136 1975 25.5835 1980 25.72663 1985 26.10311 1990 26.44661 1995 26.35571 2000 26.80982 2005 26.93228 2010 26.95846 2015 26.83793 2020 26.82323 2025 27.38453 2030 28.31781 2035 29.22998 2040 29.93893 2045 30.37382 2050 30.59445 2055 30.79726 2060 31.00064 2065 31.10264 2070 31.06495 2075 30.92329 2080 30.72142 2085 30.50085 2090 30.27671 2095 30.03234 2100 29.76335