Year	Total
1800	6.8
1801	6.8
1802	6.8
1803	6.8
1804	6.8
1805	6.8
1806	6.8
1807	6.8
1808	6.8
1809	6.8
1810	6.8
1811	6.8
1812	6.8
1813	6.8
1814	6.8
1815	6.8
1816	6.8
1817	6.8
1818	6.8
1819	6.8
1820	6.8
1821	6.8
1822	6.8
1823	6.8
1824	6.8
1825	6.8
1826	6.8
1827	6.8
1828	6.8
1829	6.8
1830	6.8
1831	6.8
1832	6.8
1833	6.8
1834	6.8
1835	6.8
1836	6.8
1837	6.8
1838	6.8
1839	6.8
1840	6.8
1841	6.8
1842	6.8
1843	6.8
1844	6.8
1845	6.8
1846	6.8
1847	6.8
1848	6.8
1849	6.8
1850	6.8
1851	6.8
1852	6.8
1853	6.8
1854	6.8
1855	6.8
1856	6.8
1857	6.8
1858	6.8
1859	6.8
1860	6.8
1861	6.8
1862	6.8
1863	6.8
1864	6.8
1865	6.8
1866	6.8
1867	6.8
1868	6.8
1869	6.8
1870	6.8
1871	6.8
1872	6.8
1873	6.8
1874	6.8
1875	6.8
1876	6.8
1877	6.8
1878	6.8
1879	6.8
1880	6.8
1881	6.8
1882	6.8
1883	6.8
1884	6.8
1885	6.8
1886	6.8
1887	6.8
1888	6.8
1889	6.8
1890	6.8
1891	6.8
1892	6.8
1893	6.8
1894	6.8
1895	6.8
1896	6.8
1897	6.8
1898	6.8
1899	6.8
1900	6.8
1901	6.52
1902	6.23
1903	6.22
1904	6.2
1905	6.19
1906	6.18
1907	6.16
1908	6.09
1909	6.01
1910	5.94
1911	5.86
1912	5.79
1913	5.72
1914	5.65
1915	5.58
1916	5.51
1917	5.44
1918	5.57
1919	5.69
1920	5.82
1921	5.94
1922	6.07
1923	6.04
1924	6.02
1925	5.99
1926	5.96
1927	5.94
1928	5.94
1929	5.95
1930	5.96
1931	5.97
1932	5.98
1933	5.95
1934	5.92
1935	5.89
1936	5.86
1937	5.83
1938	5.87
1939	5.9
1940	5.93
1941	5.96
1942	5.99
1943	6.07
1944	6.16
1945	6.24
1946	6.32
1947	6.41
1948	6.49
1949	6.58
1950	6.66
1951	6.68
1952	6.72
1953	6.74
1954	6.76
1955	6.78
1956	6.78
1957	6.78
1958	6.78
1959	6.77
1960	6.77
1961	6.76
1962	6.76
1963	6.75
1964	6.75
1965	6.76
1966	6.77
1967	6.79
1968	6.81
1969	6.83
1970	6.83
1971	6.79
1972	6.7
1973	6.56
1974	6.37
1975	6.13
1976	5.86
1977	5.59
1978	5.32
1979	5.06
1980	4.84
1981	4.64
1982	4.46
1983	4.3
1984	4.15
1985	4.02
1986	3.9
1987	3.79
1988	3.68
1989	3.57
1990	3.47
1991	3.37
1992	3.27
1993	3.18
1994	3.1
1995	3.02
1996	2.95
1997	2.88
1998	2.82
1999	2.77
2000	2.72
2001	2.67
2002	2.62
2003	2.58
2004	2.54
2005	2.5
2006	2.46
2007	2.42
2008	2.39
2009	2.36
2010	2.34
2011	2.32
2012	2.3
2013	2.27
2014	2.24
2015	2.22
2016	2.18
2017	2.15
2018	2.12