Year	Percent
1950	17.98995
1955	18.04445
1960	18.02715
1965	19.30913
1970	19.87418
1975	19.36945
1980	19.65908
1985	17.31962
1990	17.24762
1995	17.14434
2000	16.42262
2005	17.03185
2010	16.40776
2015	15.62513
2020	14.61221
2025	13.90975
2030	13.3503
2035	12.75698
2040	12.11553
2045	11.5058
2050	10.91486
2055	10.37312
2060	9.87281
2065	9.43325
2070	9.02752
2075	8.63955
2080	8.2542
2085	7.90476
2090	7.56783
2095	7.26638
2100	6.98674