1856	-2.69
1859	-2.95
1862	-3.24
1865	-2.92
1868	-3.24
1870	-3.45
1872	-3.35
1875	-3.18
1878	-2.83
1881	-3.06
1885	-3.13
1888	-3.24
1891	-2.82
1894	-3.24
1897	-3.17
1900	-3.02
1902	-2.85
1905	-2.96
1908	-3.04
1911	-2.76
1915	-2.93
1917	-3.28
1920	-3.22