Year	Total
1800	4.2
1801	4.2
1802	4.2
1803	4.2
1804	4.2
1805	4.2
1806	4.2
1807	4.2
1808	4.2
1809	4.2
1810	4.2
1811	4.2
1812	4.2
1813	4.2
1814	4.2
1815	4.2
1816	4.2
1817	4.2
1818	4.2
1819	4.2
1820	4.2
1821	4.2
1822	4.2
1823	4.2
1824	4.2
1825	4.2
1826	4.2
1827	4.2
1828	4.2
1829	4.2
1830	4.2
1831	4.2
1832	4.2
1833	4.2
1834	4.2
1835	4.2
1836	4.2
1837	4.2
1838	4.2
1839	4.2
1840	4.2
1841	4.2
1842	4.2
1843	4.2
1844	4.2
1845	4.2
1846	4.2
1847	4.2
1848	4.2
1849	4.2
1850	4.2
1851	4.13
1852	4.06
1853	3.99
1854	3.93
1855	3.86
1856	3.79
1857	3.72
1858	3.65
1859	3.58
1860	3.51
1861	3.45
1862	3.38
1863	3.31
1864	3.24
1865	3.47
1866	3.54
1867	3.53
1868	3.58
1869	3.58
1870	3.71
1871	3.67
1872	3.72
1873	3.63
1874	3.57
1875	3.51
1876	3.57
1877	3.54
1878	3.4
1879	3.44
1880	3.31
1881	3.33
1882	3.22
1883	3.15
1884	3.2
1885	3.15
1886	3.11
1887	3.1
1888	3.06
1889	3.04
1890	2.99
1891	3.05
1892	3.01
1893	3.09
1894	3.08
1895	3.12
1896	3.17
1897	3.16
1898	3.13
1899	3.09
1900	3.04
1901	2.92
1902	3.08
1903	3.09
1904	3.16
1905	3.13
1906	3.15
1907	3.11
1908	3.12
1909	3.14
1910	3.12
1911	3.07
1912	3.1
1913	3.09
1914	3.05
1915	2.99
1916	2.87
1917	2.71
1918	2.73
1919	2.75
1920	3.2
1921	2.79
1922	2.61
1923	2.74
1924	2.83
1925	2.79
1926	2.76
1927	2.72
1928	2.69
1929	2.66
1930	2.67
1931	2.61
1932	2.56
1933	2.6
1934	2.61
1935	2.63
1936	2.92
1937	2.57
1938	2.6
1939	2.56
1940	2.56
1941	2.9
1942	2.99
1943	2.93
1944	2.98
1945	3.04
1946	3.33
1947	3.46
1948	3.58
1949	3.53
1950	3.48
1951	3.45
1952	3.41
1953	3.39
1954	3.4
1955	3.44
1956	3.5
1957	3.57
1958	3.67
1959	3.76
1960	3.86
1961	3.93
1962	3.98
1963	4
1964	3.99
1965	3.95
1966	3.9
1967	3.86
1968	3.83
1969	3.82
1970	3.81
1971	3.81
1972	3.79
1973	3.74
1974	3.67
1975	3.57
1976	3.46
1977	3.34
1978	3.22
1979	3.11
1980	3
1981	2.9
1982	2.79
1983	2.68
1984	2.56
1985	2.45
1986	2.34
1987	2.23
1988	2.14
1989	2.06
1990	2
1991	1.95
1992	1.92
1993	1.9
1994	1.9
1995	1.9
1996	1.91
1997	1.92
1998	1.93
1999	1.94
2000	1.95
2001	1.96
2002	1.96
2003	1.97
2004	1.98
2005	1.98
2006	1.99
2007	1.99
2008	2
2009	2
2010	2
2011	2
2012	2
2013	2
2014	1.99
2015	1.99
2016	1.99
2017	1.98
2018	1.98