The disparity in the value of one vote among the 300 single-seat districts for the House of Representatives has grown to 2.203 to 1 from 2.064 in 2000, according to calculations based on a demographic study released Tuesday.
The number of Lower House districts where the ratio is more than 2 to 1 increased from nine to 48, including the No. 4 district in Chiba Prefecture, which had the largest population per district in the country, at 569,835 as of the 2005 census. In contrast, the No. 3 district in Kochi Prefecture had the smallest population, at 258,681 -- the base figure used to calculate the disparity.