The same table on the Wiki page says that the actual count was 289 murders in 2022. Japan had a population of over 126 million in 2020. If we used your formula, that would mean there were over 289,000 murders in Japan between 2021 and 2022. See below:
230 per 100,000 = 126,146,099 x 230 ÷ 100,000 = 290,136 murders total.
Whereas, 0.233 per 100,000 = 126,146,099 x 0.233 ÷ 100,000 = 294 murders total.
2+2=4, simple maths. But 290k murders per year would explain the population drop, lol.
For those curious+lazy, the removed sections were “pertaining to Habeas Corpus and judicial review of unlawful detention”.