Year	Percent
1950	14.7711
1955	14.80171
1960	14.54845
1965	14.28622
1970	13.99762
1975	13.7491
1980	13.53391
1985	13.27075
1990	13.17764
1995	13.59549
2000	14.06496
2005	14.68166
2010	15.44858
2015	16.27053
2020	17.22913
2025	18.15352
2030	18.81947
2035	19.46219
2040	20.36217
2045	21.29575
2050	22.27446
2055	23.00435
2060	23.42211
2065	23.77593
2070	24.13798
2075	24.58221
2080	25.01079
2085	25.37696
2090	25.66795
2095	25.90705
2100	26.11806