In the past decade, the volume of Irish whiskey sold has increased 131%, surpassing the growth rate of bourbon, 56%, and scotch, 13%. Although the spirit must be produced exclusively in Ireland, the number of distilleries has increased to 16, up four from three years ago, with plans for 11 more in the near future. While the segment, which sold about 7.8 million cases in 2015, may seem small in comparison to sales of scotch and bourbon, which sold a combined 114 million cases in 2015, growth rates indicate mounting interest in Irish whiskey, particularly from the US market. The largest brand in the US is Jameson, which dominates the market with a 78% share. The interest in Irish whiskey reflects a larger trend in the US for interest in brown spirits, which were heavily suppressed during the Prohibition era.
Source: https://www.wsj.com/articles/irish-whiskey-barrels-ahead-1477054801