Historical clue formulations

• Okinawa port — 2019-01-27
• Capital of Okinawa — 2018-07-01
• Okinawa port — 2003-11-14
• Okinawa port — 2001-09-01
• Okinawan port — 1996-09-13
• Okinawa's capital — 1996-05-02
• Okinawa's capital — 1995-10-29
• Capital of Okinawa — 1995-06-24
• Okinawan seaport — 1995-05-07