I saw that. I didn't think audiences were that low, but it was a tragically dreary production that fully deserved its lack of success. Its unfortunate audiences suffered so greatly that someone on rec.arts.theatre.musicals was inspired to set up the Tess Survivors Association. There was a TSA web page too, but it no longer exists. It's not even in the Internet Archive.
(In terms of numbing lack of eventfulness it was later overtaken - by a mile - by Behind The Iron Mask, from which audiences stumbled out into the daylight in shell-shocked horror, but in its day Tess was quite remarkable.)