Year	Number Of Units
1871	8693.00
1872	11179.0
1873	7687.00
1874	7764.00
1875	10023.0
1876	12938.0
1877	14410.0
1878	17127.0
1879	21589.0
1880	24945.0
1881	26170.0
1882	23301.0
1883	21110.0
1884	18428.0
1885	15754.0
1886	12252.0
1887	12478.0
1888	12426.0
1889	11829.0
1890	10935.0
1891	12105.0
1892	11200.0
1893	12830.0
1894	12874.0
1895	13141.0
1896	16894.0
1897	18529.0
1898	24838.0
1899	27381.0
1900	25161.0
1901	27174.0
1902	25480.0
1903	26420.0
1904	23269.0
1905	21970.0
1906	21415.0
1907	19211.0
1908	13377.0
1909	13343.0
1910	11757.0
1911	10027.0
1912	8006.00
1913	8579.00
1914	8299.00
1915	5549.00
1916	3642.00
1920	2642.00
1921	12927.0
1922	16907.0
1923	10268.0
1924	17441.0
1925	23481.0
1926	33529.0
1927	41808.0
1928	42381.0
1929	42688.0
1930	50183.0
1931	55512.0
1932	44613.0
1933	54409.0
1934	80612.0
1935	75676.0
1936	78838.0
1937	69095.0