Year	Percent
1950	19.28873
1955	21.8164
1960	21.34682
1965	20.99116
1970	20.24935
1975	18.61375
1980	17.92761
1985	17.01073
1990	17.86111
1995	19.93596
2000	21.4016
2005	22.13568
2010	21.4978
2015	21.05347
2020	21.4826
2025	21.87199
2030	21.95534
2035	21.38667
2040	20.97471
2045	20.90884
2050	21.39532
2055	22.45649
2060	23.01325
2065	23.2402
2070	23.11968
2075	22.71103
2080	22.6493
2085	22.81215
2090	22.97375
2095	22.94681
2100	22.70223