1928	18200
1929	19320
1930	15900
1931	9365
1932	24460
1933	13770
1934	7934
1935	28350
1936	7298
1937	16730
1938	27380
1939	10570
1940	11210
1941	24100
1942	29290
1943	14870
1944	14400
1945	36520
1946	24440
1947	24620
1948	16600
1949	18970
1950	30930
1951	18850
1952	13660
1953	16780
1954	10820
1955	12720
1956	8252
1957	35550
1958	22860
1959	9066
1960	17080
1961	15600
1962	15970
1963	9275
1964	6926
1965	10160
1966	10320
1967	10570
1968	25510
1969	21380
1970	13300
1971	8359
1972	12770
1973	32100
1974	24080
1975	32740
1976	8523
1977	14310
1978	7282
1979	17370
1980	8924
1981	11760