With a captip to the Crawfish Boxes for the link, we find out that ratings for Astros telecasts are down almost 19% on FS Houston.
The Sports Business Journal says that an average of 52,237 households watch Astros games on FSH, down 18.9%, drawing a 2.46 share - which is down 19.6% from last year (supposing that's the time frame).
Only nine teams draw fewer average viewers than the Astros' average: Brewers, Padres, Pirates, Indians, Orioles, Marlins, Royals, Nationals, and A's.