In 2011 the number of people who evacuated, both under government orders and voluntarily, peaked at around 165,000.
Approximately 25,000 people [1] will never be able to return to their homes.
Since 2011 some people have continued to evacuate voluntarily. In some cases this is the result of noticing changes in their health and/or the health of their children, which are consistent with the effects of chronic exposure to low-level internal radiation [2].
In 2016 86,700 people were still living as evacuees, 47,000 of whom were displaced within Fukushima prefecture.
Out of the 86,700 evacuees, 26,601 are voluntary evacuees.
According to the Yomiuri Shimbun – Japan News [3], the total number of Fukushima households which evacuated voluntarily, both within and outside Fukushima prefecture was 10,524 (26,601 people).
These households comprise:

Map from CNIC (Citizens Nuclear Information Center Japan)

Map from website of METI (Ministry of Economy, Trade and Industry)