Year Number Of Units 1867 671.000 1868 782.000 1869 1027.00 1870 749.000 1871 736.000 1872 1044.00 1873 1208.00 1874 2039.00 1875 1550.00 1876 1309.00 1877 997.000 1878 668.000 1879 580.000 1880 466.000 1881 516.000 1882 516.000 1883 533.000 1884 685.000 1885 792.000 1886 1044.00 1887 1155.00 1888 1415.00 1889 1825.00 1890 1670.00 1891 1700.00 1892 1523.00 1893 1522.00 1894 1660.00 1895 1847.00 1896 2209.00 1897 2521.00 1898 2633.00 1899 2680.00 1900 2405.00 1901 2352.00 1902 2731.00 1903 3450.00 1904 3695.00 1905 3645.00 1906 4210.00 1907 3631.00 1908 2887.00 1909 2665.00 1910 2758.00 1911 3212.00 1912 2869.00 1913 2318.00