Year	Total
1800	4.08
1801	4.11
1802	4.14
1803	4.17
1804	4.2
1805	4.23
1806	4.25
1807	4.28
1808	4.31
1809	4.34
1810	4.37
1811	4.4
1812	4.43
1813	4.43
1814	4.44
1815	4.44
1816	4.45
1817	4.45
1818	4.45
1819	4.46
1820	4.46
1821	4.47
1822	4.47
1823	4.48
1824	4.48
1825	4.48
1826	4.49
1827	4.49
1828	4.5
1829	4.5
1830	4.51
1831	4.51
1832	4.51
1833	4.52
1834	4.52
1835	4.53
1836	4.53
1837	4.54
1838	4.54
1839	4.55
1840	4.56
1841	4.58
1842	4.59
1843	4.6
1844	4.61
1845	4.62
1846	4.64
1847	4.65
1848	4.66
1849	4.67
1850	4.68
1851	4.7
1852	4.71
1853	4.72
1854	4.73
1855	4.74
1856	4.76
1857	4.77
1858	4.78
1859	4.79
1860	4.8
1861	4.82
1862	4.83
1863	4.84
1864	4.7
1865	4.55
1866	4.41
1867	4.27
1868	4.13
1869	3.98
1870	3.84
1871	3.7
1872	3.56
1873	3.41
1874	3.52
1875	3.74
1876	3.75
1877	3.67
1878	3.58
1879	3.55
1880	3.59
1881	3.77
1882	3.67
1883	3.96
1884	3.8
1885	3.98
1886	4.04
1887	4.04
1888	4.43
1889	4.54
1890	4.18
1891	3.99
1892	4.4
1893	4.26
1894	4.35
1895	4.36
1896	4.51
1897	4.66
1898	4.72
1899	4.73
1900	4.69
1901	5.01
1902	4.97
1903	4.83
1904	4.61
1905	4.52
1906	4.38
1907	5.03
1908	5.13
1909	5.16
1910	5.01
1911	5.19
1912	5.08
1913	5.07
1914	5.14
1915	4.91
1916	4.98
1917	4.95
1918	4.83
1919	4.77
1920	5.35
1921	5.22
1922	5.12
1923	5.26
1924	5.07
1925	5.22
1926	5.19
1927	5
1928	5.09
1929	4.87
1930	4.82
1931	4.76
1932	4.86
1933	4.63
1934	4.39
1935	4.59
1936	4.34
1937	4.45
1938	3.87
1939	3.79
1940	4.13
1941	4.35
1942	4.17
1943	4.1
1944	3.93
1945	3.1
1946	3.35
1947	4.48
1948	4.35
1949	4.27
1950	3.48
1951	3.34
1952	3.07
1953	2.84
1954	2.63
1955	2.46
1956	2.32
1957	2.21
1958	2.13
1959	2.07
1960	2.04
1961	2.02
1962	2.01
1963	2.01
1964	2.01
1965	2.02
1966	2.03
1967	2.04
1968	2.07
1969	2.09
1970	2.11
1971	2.12
1972	2.11
1973	2.09
1974	2.05
1975	2
1976	1.94
1977	1.89
1978	1.84
1979	1.81
1980	1.78
1981	1.77
1982	1.76
1983	1.75
1984	1.73
1985	1.71
1986	1.69
1987	1.66
1988	1.63
1989	1.6
1990	1.56
1991	1.53
1992	1.5
1993	1.47
1994	1.44
1995	1.41
1996	1.39
1997	1.37
1998	1.35
1999	1.34
2000	1.32
2001	1.31
2002	1.3
2003	1.3
2004	1.3
2005	1.31
2006	1.32
2007	1.33
2008	1.34
2009	1.36
2010	1.37
2011	1.39
2012	1.4
2013	1.42
2014	1.43
2015	1.44
2016	1.46
2017	1.47
2018	1.48