Year	Percent
1950	16.07487
1955	19.20488
1960	19.3472
1965	19.59851
1970	19.50799
1975	19.69173
1980	19.96592
1985	18.9555
1990	17.04985
1995	15.73187
2000	14.9334
2005	15.07319
2010	15.80045
2015	15.88016
2020	14.27809
2025	12.99241
2030	12.09915
2035	11.4799
2040	10.86146
2045	10.18183
2050	9.47392
2055	8.7816
2060	8.20184
2065	7.71857
2070	7.32171
2075	6.9621
2080	6.61784
2085	6.31968
2090	6.06152
2095	5.85947
2100	5.69506