Year	Total
1800	6.5
1801	6.48
1802	6.46
1803	6.44
1804	6.42
1805	6.4
1806	6.38
1807	6.36
1808	6.34
1809	6.32
1810	6.3
1811	6.28
1812	6.26
1813	6.24
1814	6.22
1815	6.2
1816	6.18
1817	6.16
1818	6.14
1819	6.12
1820	6.1
1821	6.08
1822	6.06
1823	6.04
1824	6.02
1825	6
1826	5.96
1827	5.92
1828	5.87
1829	5.83
1830	5.79
1831	5.75
1832	5.7
1833	5.66
1834	5.62
1835	5.58
1836	5.54
1837	5.49
1838	5.45
1839	5.41
1840	5.37
1841	5.32
1842	5.28
1843	5.24
1844	5.2
1845	5.16
1846	5.11
1847	5.07
1848	5.03
1849	4.99
1850	4.94
1851	5.01
1852	4.7
1853	5.03
1854	4.86
1855	5.32
1856	5.19
1857	5.63
1858	5.71
1859	5.75
1860	5.71
1861	5.67
1862	5.8
1863	5.59
1864	5.75
1865	5.64
1866	5.33
1867	5.41
1868	5.43
1869	5.19
1870	5.19
1871	5.09
1872	4.97
1873	5.01
1874	4.93
1875	4.81
1876	4.81
1877	4.69
1878	4.74
1879	4.8
1880	4.73
1881	4.73
1882	4.62
1883	4.66
1884	4.77
1885	4.78
1886	4.74
1887	4.77
1888	4.76
1889	4.65
1890	4.69
1891	4.62
1892	4.52
1893	4.4
1894	4.13
1895	4.07
1896	3.81
1897	3.78
1898	3.64
1899	3.66
1900	3.66
1901	3.64
1902	3.58
1903	3.39
1904	3.54
1905	3.51
1906	3.35
1907	3.35
1908	3.35
1909	3.35
1910	3.35
1911	3.51
1912	3.51
1913	3.51
1914	3.51
1915	3.51
1916	3.07
1917	3.07
1918	3.07
1919	3.07
1920	3.07
1921	3.12
1922	3.11
1923	3.02
1924	2.97
1925	2.95
1926	2.85
1927	2.8
1928	2.77
1929	2.64
1930	2.58
1931	2.36
1932	2.19
1933	2.17
1934	2.11
1935	2.12
1936	2.18
1937	2.21
1938	2.21
1939	2.22
1940	2.26
1941	2.36
1942	2.38
1943	2.57
1944	2.63
1945	2.74
1946	2.99
1947	3.08
1948	2.99
1949	2.99
1950	3.07
1951	3.06
1952	3.18
1953	3.19
1954	3.2
1955	3.28
1956	3.33
1957	3.42
1958	3.42
1959	3.44
1960	3.44
1961	3.52
1962	3.41
1963	3.32
1964	3.16
1965	3
1966	2.92
1967	2.87
1968	2.88
1969	2.86
1970	2.81
1971	2.85
1972	2.68
1973	2.48
1974	2.33
1975	2.18
1976	2.09
1977	2.03
1978	1.97
1979	1.92
1980	1.9
1981	1.92
1982	1.91
1983	1.91
1984	1.86
1985	1.9
1986	1.87
1987	1.86
1988	1.85
1989	1.85
1990	1.88
1991	1.86
1992	1.87
1993	1.85
1994	1.84
1995	1.82
1996	1.81
1997	1.79
1998	1.77
1999	1.76
2000	1.76
2001	1.76
2002	1.78
2003	1.79
2004	1.82
2005	1.86
2006	1.89
2007	1.92
2008	1.94
2009	1.94
2010	1.93
2011	1.92
2012	1.9
2013	1.89
2014	1.87
2015	1.86
2016	1.85
2017	1.84
2018	1.83