Feb 25th seems to predate the reports of the more comprehensive testing that found the near 50% asymptomatic rate.
In particular, that CDC report I linked above citing 46.5% is from late March (early release on March 23, published on March 27th).
That report cites a website by the Japanese Ministry of Health, Labour and Welfare [1], which itself confirms that 46.5% (331/712) is up-to-date as of March 26th.
I'm not very knowledgeable about stats, to be perfect honest, but I think your paper must've turned out to be a red herring. Maybe they got unlucky with their sample?
In particular, that CDC report I linked above citing 46.5% is from late March (early release on March 23, published on March 27th).
That report cites a website by the Japanese Ministry of Health, Labour and Welfare [1], which itself confirms that 46.5% (331/712) is up-to-date as of March 26th.
I'm not very knowledgeable about stats, to be perfect honest, but I think your paper must've turned out to be a red herring. Maybe they got unlucky with their sample?
[1] https://www.mhlw.go.jp/stf/seisakunitsuite/bunya/newpage_000...