Um, "its", not "it's".

But anyway, interesting question.  There's actually two ways of looking at the data from The Wayback Machine:

all time satoshi high around mid-March, 2016:

http://web.archive.org/web/20160315170717/http://coinmarketcap.com/currencies/ethereum/#markets

all-time market cap high around mid-June 2016:

http://web.archive.org/web/20160611035722/http://coinmarketcap.com/currencies/ethereum/#markets

At the March 2016 high, there were around 3.5 ETH sold on Poloniex for every ETH sold on Kraken.  By the time of the June 2016 high that ratio was more like 2.0X.  Conclusion: ICN really, REALLY needs to get on Poloniex.