Year	Percent
1950	31.60033
1955	31.80907
1960	30.72396
1965	29.11322
1970	27.41767
1975	26.35938
1980	27.20783
1985	28.80012
1990	30.21315
1995	31.87073
2000	32.57304
2005	31.99183
2010	29.70187
2015	25.17136
2020	21.49967
2025	20.18152
2030	20.60186
2035	20.85735
2040	20.94157
2045	20.24014
2050	19.06253
2055	18.62549
2060	18.81656
2065	19.47753
2070	20.16306
2075	20.49039
2080	20.35095
2085	19.94711
2090	19.63851
2095	19.59731
2100	19.74128