Year	Percent
1950	29.28624
1955	28.47544
1960	27.3771
1965	26.30876
1970	25.34207
1975	25.19215
1980	26.08792
1985	27.04185
1990	27.70495
1995	28.07747
2000	28.99251
2005	29.64561
2010	30.04094
2015	30.28692
2020	30.25653
2025	30.20386
2030	30.30489
2035	30.67618
2040	30.99478
2045	31.17727
2050	31.15462
2055	30.93762
2060	30.74591
2065	30.5945
2070	30.45709
2075	30.29163
2080	30.08192
2085	29.84461
2090	29.61178
2095	29.38847
2100	29.18031