Year	Percent
1950	29.9278
1955	28.41314
1960	29.34085
1965	28.31599
1970	28.05018
1975	29.27102
1980	29.71456
1985	28.66305
1990	28.07529
1995	27.24007
2000	28.40352
2005	29.51088
2010	28.73491
2015	27.60816
2020	25.02978
2025	23.96163
2030	23.26526
2035	21.95196
2040	21.75179
2045	21.7161
2050	21.49073
2055	21.42806
2060	21.32136
2065	21.2617
2070	21.24386
2075	21.3176
2080	21.40606
2085	21.42221
2090	21.37629
2095	21.28025
2100	21.15845