Source for market cap data: coinmarketcap.
Data: $ 19 billion on April 14, 2017 and $ 3.3 billion on April 13, 2015.
Source for hash rate data: blockchain.info.
Data: 3,217,588 tera on April 14, 2017 and 336,745 tera on April 19, 2015.
It doesn't take a large percentage for either side to reach at least the network effect of two years ago.