Year	Years
1800	30.7
1801	30.7
1802	30.7
1803	30.7
1804	30.7
1805	30.7
1806	30.7
1807	30.7
1808	30.7
1809	30.7
1810	30.7
1811	30.7
1812	30.7
1813	30.7
1814	30.7
1815	30.7
1816	30.7
1817	30.7
1818	30.7
1819	30.7
1820	30.7
1821	30.7
1822	30.7
1823	30.7
1824	30.7
1825	30.7
1826	30.7
1827	30.7
1828	30.7
1829	30.7
1830	30.7
1831	30.7
1832	30.7
1833	30.7
1834	30.7
1835	30.7
1836	30.7
1837	30.7
1838	30.7
1839	30.7
1840	30.7
1841	30.7
1842	30.7
1843	30.7
1844	30.7
1845	30.7
1846	30.7
1847	30.7
1848	30.7
1849	30.7
1850	30.7
1851	30.7
1852	30.7
1853	30.7
1854	30.7
1855	30.7
1856	30.7
1857	30.7
1858	30.7
1859	30.7
1860	30.7
1861	30.7
1862	30.7
1863	30.7
1864	30.7
1865	30.7
1866	30.7
1867	30.7
1868	30.7
1869	30.7
1870	30.7
1871	30.72
1872	30.74
1873	30.75
1874	30.77
1875	30.79
1876	30.81
1877	30.83
1878	30.84
1879	30.86
1880	30.88
1881	30.9
1882	30.92
1883	30.94
1884	30.95
1885	30.97
1886	30.99
1887	31.01
1888	31.03
1889	31.04
1890	31.06
1891	31.08
1892	31.1
1893	31.12
1894	31.13
1895	31.15
1896	31.17
1897	31.19
1898	31.21
1899	31.22
1900	31.24
1901	31.26
1902	31.28
1903	31.3
1904	31.31
1905	31.33
1906	31.35
1907	31.37
1908	31.39
1909	31.41
1910	31.42
1911	31.44
1912	31.46
1913	31.48
1914	31.5
1915	31.51
1916	31.53
1917	31.55
1918	26.17
1919	31.59
1920	31.6
1921	31.62
1922	31.64
1923	31.66
1924	31.68
1925	31.69
1926	31.71
1927	31.73
1928	31.75
1929	31.77
1930	31.78
1931	31.8
1932	31.82
1933	31.84
1934	31.86
1935	31.88
1936	31.89
1937	31.91
1938	31.93
1939	31.95
1940	31.97
1941	31.98
1942	32
1943	32.02
1944	32.04
1945	32.06
1946	34.31
1947	36.58
1948	38.84
1949	41.1
1950	43.36
1951	44.03
1952	45.34
1953	46.62
1954	47.88
1955	49.11
1956	50.33
1957	51.51
1958	52.69
1959	53.84
1960	54.98
1961	56.11
1962	57.24
1963	58.35
1964	59.45
1965	60.52
1966	61.56
1967	62.56
1968	63.51
1969	64.4
1970	65.24
1971	66.25
1972	66.82
1973	67.3
1974	67.84
1975	68.35
1976	68.86
1977	69.37
1978	69.79
1979	70.27
1980	70.84
1981	71.31
1982	71.71
1983	71.8
1984	72.24
1985	72.45
1986	72.51
1987	72.57
1988	72.57
1989	72.63
1990	72.77
1991	72.94
1992	73.1
1993	73.24
1994	73.37
1995	73.53
1996	73.72
1997	73.95
1998	74.3
1999	74.51
2000	74.83
2001	75.08
2002	75.36
2003	75.76
2004	76.23
2005	76.59
2006	76.82
2007	76.83
2008	76.75
2009	76.63
2010	76.51
2011	76.45
2012	76.42
2013	76.42
2014	76.43
2015	76.48
2016	76.58
2017	76.74
2018	76.89