How many volumes were held by library serving the southernmost prefecture of Japan in 2016?
Okinawa Prefectural Library: Okinawa Prefectural Library (沖縄県立図書館 , Okinawa Kenritsu Toshokan ) opened in Naha, Okinawa Prefecture, Japan in 1910. Okinawa Prefectural Library:  As of 2016, the collection numbers some 708,000 items, of which almost a fifth are on open access.
i don't know