Year	Not Specified
1874	7.73
1875	7.71
1876	8.16
1877	7.
1878	7.
1879	6.77
1880	6.8
1881	9.69
1882	10.39
1883	12.1
1884	14.37
1885	19.67
1886	19.15
1887	20.19
1888	22.46
1889	26.44
1890	24.33
1891	22.26
1892	22.98
1893	14.86
1894	13.59
1895	14.22
1896	13.14
1897	16.61
1898	15.67
1899	23.25
1900	16.50
1901	18.20
1902	18.55
1903	23.95
1904	42.03
1905	66.66
1906	65.07
1907	64.15
1908	39.83
1909	60.13
1910	34.81
1911	32.60
1912	36.47
1913	30.72
1914	38.27
1915	40.30
1916	35.40
1917	27.61
1918	17.86
1919	68.14
1920	56.33
1921	114.30
1922	169.51
1923	252.6
1924	202.05
1925	196.17
1926	232.75
1927	185.23
1928	161.72
1929	98.01
1930	61.76
1931	51.42
1932	18.23
1933	9.36
1934	10.36
1935	29.56