It is hard to say when will bitcoin rise to that amount. But every bitcoin user are hooping that it will rise again up to 20000$ or may be more.
Well I think it is not very hard to see the price high once again, now more people are using bitcoin for the sake of save future, bitcoin is being use all over the world more than any crypto currency, most of companies are now switching to the blockchain technology so I think bitcoin will be more than 20k dollar at the end of 2018, this is fine predication of some expert investors.