 The Northwest Pacific Ocean is the most active basin on the planet, accounting for one-third of all tropical cyclone activity.Annually, an average of 25.7 tropical cyclones in the basin acquire tropical storm strength or greater; also, an average of 16 typhoons occurred each year during the 1968–1989 period.The basin occupies all the territory north of the equator and west of the International Date Line, including the South China Sea.