Year	Percent
1950	29.4625
1955	31.25225
1960	33.19226
1965	30.72613
1970	29.65803
1975	29.72108
1980	29.24774
1985	29.74621
1990	28.51805
1995	27.31173
2000	26.7301
2005	26.92361
2010	26.78798
2015	26.07044
2020	25.01533
2025	24.25745
2030	23.05241
2035	22.24532
2040	21.88517
2045	21.54682
2050	21.44249
2055	21.28223
2060	21.03168
2065	20.79161
2070	20.67334
2075	20.67604
2080	20.72134
2085	20.74865
2090	20.69321
2095	20.57123
2100	20.45599