How long has it been since Similarworld is created?

Hi Guys, I was a member in Experienceproject and had been trying to find a similar website. Well, at that time (probs 2015), I pretty give up finding that my substitute for EP.

It was only today that I stumbled upon similar worlds and it already have a huge database of stories. SO my question is, how long has it been since similarworld is first created? Do I miss a lot of stuff?