According to CoinDesk: This CoinDesk listed bitcoin in less than $ 10,000 a year ago, it was less than $ 800 a year ago, and It's a surprising number to think just a week ago. Now it has reached an irritable pitch on Bitcoin. This calculates the average; the price of bitcoin is based on the data of four popular exchanges. This bitcoin reached $ 17,000 for the first time on Thursday.
source - http://money.cnn.com/2017/12/06/investing/bitcoin-rally-hits-14000/index.html