According to Japanese media, the audit has so far identified 281 centenarians who are missing or have already died.
Those unaccounted for include a 125-year-old woman whose registered address was turned into a park in 1981, according to media reports.
There are more than 40,000 registered centenarians in Japan, according to government data, but the number of missing has raised concerns that the welfare system is being exploited by dishonest relatives.
Not sure about the maths here, but 40,000 people over 100 are presumably "being replaced" at a fair rate. Assuming that on average they live 5 years then 8,000 die every year, about 22 a day. So 281 "missing" is less than 2 weeks "turnover". Given the delays in reporting deaths and the associated paperwork, that could easily explain all the discrepancy.