Just because you have it doesn't represent the majority of the f2ps....

It depends on the content. Before it was two years for every content the China server is added onto their server, which is easy to track. Now, if it's an ninja/item Oasis thinks believes should be expensive (place it in Tsukuyomi rebate), it will be less than 2 months. For event ninjas and skill breaks, anywhere from 2-6 months. The free ninja skillbreaks are taking longer while the event ninjas are released before them. For new daily events, it's been almost 2 years in counting.