Performance is measured by sorting expected returns from lowest to highest. The population includes: a) Before Apr, 2004: roughly the largest 450 Japanese stocks plus additional stocks that were in the MXJP index plus stocks that are requested by individual clients; b) After Apr, 2004: the top 1,600 companies by market capitalization. Then we divide the list into 10 groupings, or deciles. So, assuming, in a given month, there are 1,600 companies in the universe, decile 1 (lowest expected return) would have 160 stocks.
