Year	Percent
1950	27.58957
1955	27.66063
1960	27.48018
1965	27.29078
1970	26.91732
1975	26.47487
1980	26.11256
1985	26.03376
1990	26.12008
1995	26.49665
2000	28.59536
2005	29.64816
2010	30.10105
2015	29.8805
2020	29.65445
2025	30.01314
2030	30.68118
2035	31.35603
2040	31.72191
2045	31.62296
2050	31.36119
2055	31.20587
2060	31.15594
2065	31.08045
2070	30.88478
2075	30.62112
2080	30.33652
2085	30.08814
2090	29.87445
2095	29.63805
2100	29.37476