A tremendous increase in BITCOIN value

Hi there!
I was just doing a study on the value of bitcoin and found that there is per year increase in the value of bitcoin.
Here I provide the last five years bitcoin value. and we see a good worth increase.

As we see from the graph the value of bitcoin is increasing:-

• In 2013
  1 bitcoin = 212.7 USD (approx)
• In 2014
  1 bitcoin = 425.3 USD (approx)
• In 2015
  1 bitcoin = 430.4 USD
• In 2016
  1 bitcoin= 973.4 USD
• In 2017
  1 bitcoin = 2591.8 USD
• In 2018
  1 bitcoin = x?

Now here is your work to find the 'x'
and guess in the comment section below.

Thanks for your time. :)