1851	0.19
1852	0.19
1853	0.29
1854	0.29
1855	0.28
1856	0.28
1857	0.28
1858	0.28
1859	0.28
1860	0.28
1861	0.28
1862	0.28
1863	0.28
1864	0.28
1865	0.28
1866	0.28
1867	0.28
1868	0.28
1869	0.28
1870	0.28
1871	0.27
1872	0.27
1873	0.27
1874	0.27
1875	0.25
1876	0.25
1877	0.34
1878	0.34
1879	0.32
1880	0.32
1881	0.31
1882	0.31
1883	0.3
1884	0.29
1885	0.28
1886	0.28
1887	0.27
1888	0.27
1889	0.36
1890	0.36
1891	0.35
1892	0.36
1893	0.35
1894	0.36
1895	0.35
1896	0.36
1897	0.35
1898	0.36
1899	0.35
1900	0.36
1901	0.36
1902	0.37
1903	0.37
1904	0.39
1905	0.5
1906	0.5
1907	0.5
1908	0.5
1909	0.5
1910	0.5
1911	0.5
1912	0.5
1913	0.49
1914	0.49
1915	0.51
1916	0.62
1917	0.62
1918	0.62
1919	0.62
1920	0.61
1921	0.62
1922	0.62
1923	0.61
1924	0.61
1925	0.6
1926	0.7
1927	0.68
1928	0.68
1929	0.7
1930	0.7
1931	0.71
1932	0.72
1933	0.73
1934	0.83
1935	0.82
1936	0.82
1937	0.83
1938	0.84
1939	0.85
1940	0.85
1941	0.84
1942	0.83
1943	0.82
1944	0.82
1945	0.8
1946	0.78
1947	0.77
1948	0.76
1949	0.74
1950	0.72
1951	0.72
1952	0.82
1953	0.81
1954	0.78
1955	0.75
1956	0.74
1957	0.73
1958	0.7
1959	0.78
1960	0.76
1961	0.75
1962	0.73
1963	0.8
1964	0.77
1965	0.75
1966	0.73
1967	0.81
1968	0.79
1969	0.78
1970	0.87
1971	0.86
1972	0.83
1973	0.89
1974	0.85
1975	0.93
1976	0.96
1977	1.12
1978	1.19
1979	1.22
1980	1.3
1981	1.25
1982	1.3
1983	1.25
1984	1.29
1985	1.26
1986	1.35
1987	1.39
1988	1.47
1989	1.62
1990	1.59
1991	1.56
1992	1.61
1993	1.55
1994	1.49
1995	1.57
1996	1.56
1997	1.7
1998	1.86
1999	1.91
2000	2.02
2001	2