Year	Number
1832	2
1833	2
1834	2
1835	2
1836	2
1837	2
1838	2
1839	2
1840	2
1841	2
1842	2
1843	2
1844	2
1845	2
1846	2
1847	2
1848	2
1849	2
1850	2
1851	2
1852	2
1853	2
1854	2
1855	2
1856	2
1857	2
1858	2
1859	2
1860	0
1861	-5
1862	-5
1863	-5
1864	-5
1865	-5
1866	-5
1867	8
1868	8
1869	8
1870	8
1871	8
1872	8
1873	8
1874	8
1875	8
1876	8
1877	8
1878	8
1879	8
1880	8
1881	8
1882	8
1883	8
1884	8
1885	8
1886	-3
1887	-3
1888	-3
1889	-3
1890	-3
1891	-3
1892	-3
1893	-3
1894	-3
1895	-3
1896	-3
1897	-3
1898	-3
1899	-3
1900	0
1901	0
1902	0
1903	0
1904	-5
1905	-5
1906	-5
1907	-5
1908	-5
1909	-5
1910	-5
1911	-5
1912	-5
1913	-5
1914	-5
1915	-5
1916	-5
1917	-5
1918	-5
1919	-5
1920	-5
1921	-5
1922	-5
1923	-5
1924	-5
1925	-5
1926	-5
1927	-5
1928	-5
1929	-5
1930	5
1931	5
1932	5
1933	5
1934	5
1935	5
1936	5
1937	5
1938	5
1939	5
1940	5
1941	5
1942	5
1943	5
1944	5
1945	5
1946	5
1947	5
1948	-5
1949	-5
1950	-5
1951	-5
1952	-5
1953	-5
1954	-5
1955	-5
1956	-5
1957	7
1958	7
1959	7
1960	7
1961	7
1962	7
1963	7
1964	7
1965	7
1966	7
1967	7
1968	7
1969	7
1970	7
1971	7
1972	7
1973	7
1974	8
1975	8
1976	8
1977	8
1978	8
1979	8
1980	8
1981	8
1982	8
1983	8
1984	8
1985	8
1986	8
1987	8
1988	8
1989	8
1990	8
1991	9
1992	9
1993	9
1994	9
1995	7
1996	7
1997	7
1998	7
1999	7
2000	7
2001	7
2002	7
2003	7
2004	7
2005	7
2006	7
2007	7
2008	7
2009	7
2010	7
2011	7