Japan posted its lowest annual population growth rate since a government survey began in 1968, the Home Affairs Ministry reported. The increasing role of women in the work place and the high cost of educating children were major reasons for the sluggish 0.33% annual growth rate, an official said. The lowest previous rate was 0.38% in 1989, and the high was 2.22% in 1973. The latest report, for the year ended March 31, listed Japan's population at 122.7 million.