March 1949	October 1952	January 1953	June 1954	September 1955	December 1963
May 1966	September 1966	November 1966	January 1967	February 1967	March 1968
May 1968	July 1968	September 1968	January 1969	May 1969	July 1969
September/October 1969	January/February 1970	July/August 1970	December 1970	Summer 1971	December 1971
Summer 1972	November 1972	January/February 1973	March/April 1973	January/February 1974