Year	Total
1800	6.1
1801	6.1
1802	6.1
1803	6.1
1804	6.1
1805	6.1
1806	6.1
1807	6.1
1808	6.1
1809	6.1
1810	6.1
1811	6.1
1812	6.1
1813	6.1
1814	6.1
1815	6.1
1816	6.1
1817	6.1
1818	6.1
1819	6.1
1820	6.1
1821	6.1
1822	6.1
1823	6.1
1824	6.1
1825	6.1
1826	6.1
1827	6.1
1828	6.1
1829	6.1
1830	6.1
1831	6.1
1832	6.1
1833	6.1
1834	6.1
1835	6.1
1836	6.1
1837	6.1
1838	6.1
1839	6.1
1840	6.1
1841	6.1
1842	6.1
1843	6.1
1844	6.1
1845	6.1
1846	6.1
1847	6.1
1848	6.1
1849	6.1
1850	6.1
1851	6.1
1852	6.1
1853	6.1
1854	6.1
1855	6.1
1856	6.1
1857	6.1
1858	6.1
1859	6.1
1860	6.1
1861	6.1
1862	6.1
1863	6.1
1864	6.1
1865	6.1
1866	6.1
1867	6.1
1868	6.1
1869	6.1
1870	6.1
1871	6.1
1872	6.1
1873	6.1
1874	6.1
1875	6.1
1876	6.1
1877	6.1
1878	6.1
1879	6.1
1880	6.1
1881	6.1
1882	6.1
1883	6.1
1884	6.1
1885	6.1
1886	6.1
1887	6.1
1888	6.1
1889	6.1
1890	6.1
1891	6.1
1892	6.1
1893	6.1
1894	6.1
1895	6.1
1896	6.1
1897	6.1
1898	6.1
1899	6.1
1900	6.1
1901	6.1
1902	6.1
1903	6.11
1904	6.11
1905	6.11
1906	6.11
1907	6.12
1908	6.12
1909	6.12
1910	6.12
1911	6.12
1912	6.13
1913	6.13
1914	6.13
1915	6.13
1916	6.14
1917	6.14
1918	6.14
1919	6.14
1920	6.14
1921	6.14
1922	6.14
1923	6.14
1924	6.08
1925	6.03
1926	5.97
1927	5.92
1928	5.86
1929	5.91
1930	5.96
1931	6
1932	6.05
1933	6.1
1934	6.12
1935	6.14
1936	6.16
1937	6.18
1938	6.2
1939	6.16
1940	6.12
1941	6.08
1942	6.04
1943	6
1944	5.42
1945	4.84
1946	4.26
1947	3.68
1948	3.1
1949	2.53
1950	1.95
1951	2.41
1952	3.25
1953	3.92
1954	4.44
1955	4.79
1956	4.98
1957	5.03
1958	4.96
1959	4.79
1960	4.58
1961	4.36
1962	4.17
1963	4.06
1964	4.02
1965	4.06
1966	4.16
1967	4.26
1968	4.33
1969	4.35
1970	4.32
1971	4.21
1972	4.05
1973	3.85
1974	3.63
1975	3.4
1976	3.2
1977	3.03
1978	2.9
1979	2.82
1980	2.77
1981	2.75
1982	2.73
1983	2.7
1984	2.65
1985	2.58
1986	2.5
1987	2.43
1988	2.37
1989	2.32
1990	2.29
1991	2.26
1992	2.24
1993	2.2
1994	2.16
1995	2.12
1996	2.08
1997	2.04
1998	2.01
1999	2
2000	1.99
2001	1.99
2002	1.99
2003	2
2004	2
2005	2
2006	2
2007	2
2008	1.99
2009	1.99
2010	1.98
2011	1.97
2012	1.96
2013	1.95
2014	1.93
2015	1.92
2016	1.91
2017	1.9
2018	1.89