Year	Percent
1950	9.7285
1955	10.61887
1960	10.86256
1965	10.55967
1970	9.7568
1975	9.77198
1980	11.5361
1985	11.93797
1990	12.22596
1995	11.13866
2000	11.33783
2005	10.60955
2010	10.09177
2015	10.03332
2020	9.70798
2025	9.71013
2030	9.77621
2035	9.17272
2040	8.61706
2045	8.18065
2050	7.90239
2055	7.70702
2060	7.4563
2065	7.12606
2070	6.75409
2075	6.45157
2080	6.21912
2085	6.04782
2090	5.88633
2095	5.71269
2100	5.54162
