Year	Total
1800	6.45
1801	6.41
1802	6.38
1803	6.34
1804	6.3
1805	6.26
1806	6.23
1807	6.19
1808	6.12
1809	6.04
1810	5.97
1811	5.89
1812	5.82
1813	6.01
1814	6.2
1815	6.39
1816	6.58
1817	6.77
1818	6.79
1819	6.82
1820	6.85
1821	6.87
1822	6.9
1823	6.96
1824	7.02
1825	7.08
1826	7.14
1827	7.2
1828	7.1
1829	7.01
1830	6.91
1831	6.82
1832	6.73
1833	6.6
1834	6.46
1835	6.33
1836	6.2
1837	6.07
1838	6.01
1839	5.96
1840	5.9
1841	5.85
1842	5.79
1843	5.87
1844	5.94
1845	6.02
1846	6.1
1847	6.18
1848	6.23
1849	6.28
1850	6.34
1851	6.39
1852	6.45
1853	6.44
1854	6.43
1855	6.42
1856	6.41
1857	6.41
1858	6.42
1859	6.44
1860	6.46
1861	6.48
1862	6.5
1863	6.47
1864	6.45
1865	6.42
1866	6.39
1867	6.37
1868	6.39
1869	6.42
1870	6.45
1871	6.48
1872	6.51
1873	6.43
1874	6.35
1875	6.27
1876	6.19
1877	6.07
1878	5.94
1879	5.82
1880	5.97
1881	6.13
1882	6.29
1883	6.45
1884	6.61
1885	6.77
1886	6.9
1887	7.2
1888	6.73
1889	6.07
1890	5.79
1891	6.18
1892	6.45
1893	6.41
1894	6.5
1895	6.37
1896	6.51
1897	6.57
1898	6.38
1899	6.37
1900	6.36
1901	6.35
1902	6.35
1903	6.34
1904	5.07
1905	5.48
1906	4.86
1907	5.55
1908	5.8
1909	5.17
1910	5.83
1911	5.94
1912	5.92
1913	5.96
1914	6.32
1915	5.95
1916	6
1917	6.04
1918	5.82
1919	5.33
1920	5.84
1921	5.95
1922	5.99
1923	6.06
1924	5.99
1925	5.91
1926	5.84
1927	6.07
1928	6.1
1929	6.1
1930	5.74
1931	5.74
1932	5.71
1933	5.72
1934	5.51
1935	5.53
1936	5.65
1937	5.8
1938	5.68
1939	5.62
1940	5.56
1941	5.66
1942	5.76
1943	5.86
1944	5.96
1945	6.06
1946	6.19
1947	6.33
1948	6.47
1949	6.61
1950	6.76
1951	6.88
1952	6.99
1953	7.09
1954	7.17
1955	7.19
1956	7.2
1957	7.2
1958	7.2
1959	7.18
1960	7.15
1961	7.09
1962	7.02
1963	6.95
1964	6.87
1965	6.78
1966	6.69
1967	6.59
1968	6.49
1969	6.38
1970	6.26
1971	6.15
1972	6.04
1973	5.93
1974	5.82
1975	5.72
1976	5.61
1977	5.51
1978	5.4
1979	5.29
1980	5.18
1981	5.08
1982	4.98
1983	4.88
1984	4.8
1985	4.71
1986	4.63
1987	4.55
1988	4.48
1989	4.4
1990	4.32
1991	4.25
1992	4.18
1993	4.11
1994	4.06
1995	4.01
1996	3.96
1997	3.92
1998	3.89
1999	3.85
2000	3.81
2001	3.77
2002	3.71
2003	3.65
2004	3.58
2005	3.5
2006	3.43
2007	3.35
2008	3.28
2009	3.21
2010	3.16
2011	3.11
2012	3.07
2013	3.03
2014	2.99
2015	2.96
2016	2.93
2017	2.89
2018	2.86