Year	Total
1800	4.6
1801	4.6
1802	4.6
1803	4.6
1804	4.6
1805	4.6
1806	4.6
1807	4.6
1808	4.6
1809	4.6
1810	4.6
1811	4.6
1812	4.6
1813	4.6
1814	4.6
1815	4.6
1816	4.6
1817	4.6
1818	4.6
1819	4.6
1820	4.6
1821	4.6
1822	4.6
1823	4.6
1824	4.6
1825	4.6
1826	4.6
1827	4.6
1828	4.6
1829	4.6
1830	4.6
1831	4.6
1832	4.6
1833	4.6
1834	4.6
1835	4.6
1836	4.6
1837	4.6
1838	4.6
1839	4.6
1840	4.6
1841	4.6
1842	4.6
1843	4.6
1844	4.6
1845	4.6
1846	4.6
1847	4.6
1848	4.6
1849	4.6
1850	4.6
1851	4.6
1852	4.6
1853	4.6
1854	4.6
1855	4.6
1856	4.6
1857	4.6
1858	4.6
1859	4.6
1860	4.6
1861	4.6
1862	4.6
1863	4.6
1864	4.6
1865	4.6
1866	4.6
1867	4.6
1868	4.6
1869	4.6
1870	4.6
1871	4.6
1872	4.6
1873	4.6
1874	4.6
1875	4.6
1876	4.6
1877	4.6
1878	4.6
1879	4.6
1880	4.6
1881	4.6
1882	4.6
1883	4.6
1884	4.6
1885	4.6
1886	4.6
1887	4.6
1888	4.6
1889	4.6
1890	4.6
1891	4.6
1892	4.6
1893	4.6
1894	4.6
1895	4.6
1896	4.6
1897	4.6
1898	4.6
1899	4.6
1900	4.6
1901	4.6
1902	4.6
1903	4.6
1904	4.6
1905	4.6
1906	4.6
1907	4.6
1908	4.6
1909	4.6
1910	4.6
1911	4.6
1912	4.6
1913	4.6
1914	4.6
1915	4.6
1916	4.6
1917	4.6
1918	4.6
1919	4.6
1920	4.6
1921	4.6
1922	4.6
1923	4.6
1924	4.6
1925	4.6
1926	4.42
1927	4.25
1928	4.07
1929	3.89
1930	3.72
1931	3.54
1932	3.36
1933	3.57
1934	3.78
1935	3.98
1936	4.19
1937	4.4
1938	4.61
1939	3.75
1940	4.21
1941	3.77
1942	4.43
1943	4.61
1944	4.79
1945	4.96
1946	5.14
1947	5.33
1948	5.51
1949	5.69
1950	5.87
1951	5.97
1952	6.13
1953	6.27
1954	6.37
1955	6.45
1956	6.5
1957	6.53
1958	6.54
1959	6.53
1960	6.49
1961	6.4
1962	6.28
1963	6.13
1964	5.96
1965	5.77
1966	5.58
1967	5.39
1968	5.22
1969	5.06
1970	4.91
1971	4.78
1972	4.64
1973	4.51
1974	4.37
1975	4.24
1976	4.1
1977	3.97
1978	3.84
1979	3.73
1980	3.62
1981	3.53
1982	3.45
1983	3.38
1984	3.32
1985	3.27
1986	3.22
1987	3.16
1988	3.11
1989	3.05
1990	2.98
1991	2.91
1992	2.83
1993	2.75
1994	2.67
1995	2.59
1996	2.51
1997	2.42
1998	2.33
1999	2.25
2000	2.16
2001	2.07
2002	1.98
2003	1.9
2004	1.82
2005	1.75
2006	1.7
2007	1.67
2008	1.65
2009	1.65
2010	1.65
2011	1.67
2012	1.69
2013	1.7
2014	1.71
2015	1.71
2016	1.71
2017	1.71
2018	1.71