I think in general motorcycle sales are down. The younger crowd really don't seem to have the two wheeled interest as in the past. The little bikes and hipsters seem to get along OK so Triumph in the US did well in 2016.
They sold 13000 units in the US, the most ever in the history of Triumph according the the link.
LinkTwo big dealers in the last 5 years around me closed. Not sure where they are selling them. If I do see a Triumph it is usually a Bonneville.