Wandering off by people with dementia continues to be a serious problem in Japan's rapidly aging society, with a record 15,863 such people reported missing in 2017, police data showed Thursday.

A total of 227 could not be found by the end of the year, according to the National Police Agency. The number of missing person reports increased 431 from 2016 and represented a 65 percent rise from 2012 when comparable data became available.

Local police have been working with municipal authorities to more quickly find wandering dementia patients, and some introduced new methods such as storing biometric data of dementia patients for quicker and accurate identification.

Some 14 percent of Japan's 127 million population are aged 75 or older. The number of elderly with dementia in the country is expected to reach 7 million in 2025, according to a government estimate.

Including those reported missing in previous years, the whereabouts of 10,129 people were located by the police in 2017, 5,037 returned home themselves or were found by their families, and 470 were found dead.

The survey showed 72.7 percent were located on the day their disappearance was reported to police. Some 99.3 percent were found within a week.

The overall number of people who went missing last year, including those not suffering dementia, stood at 84,850.

Of the total, 55,939 people were feared to have been involved in crimes and accidents or to have committed suicide, according to the agency.