The recent boom in Gotham tourism prompted a related spike in Broadway ticket sales to domestic tourists, according to a recent demographic report on the 2010-11 season from the Broadway League. But even though international tourism numbers were up for the city overall, Rialto sales to foreigners logged an unexpected decline.The discrepancy was one of the few surprises in the report, which found that, as in prior years, the average Main Stem theatergoer was white, wealthy, well educated and female. Last season, in fact, the Broadway showgoer was whiter than ever: Caucasians accounted for more than 82% of the season’s 12.5 million theatergoers vs. 76% of the 11.9 million attendees in 2009-10. The average age downticked from 45 to 44, although the change is likely too minor to prove terribly encouraging to those in the biz who worry about the graying of legit auds. It’s not clear what caused the 10% decline in tickets sales to international tourists, who last season shelled out for 1.77 million ducats vs. 1.96 million the season prior. (By contrast, sales to domestic visitors rose by about 10%, from around 5.5 million in 2009-10 to almost 6 million last season.) One contributing factor may have been the season’s lineup of shows, with last season noted for its preponderance of new musical offerings. In most cases, it’s older shows — which have had time to cultivate a global profile — that pull in foreigners. Besides, the new titles likely to prove the biggest draws to international crowds — “The Book of Mormon” with its “South Park” ties, Daniel Radcliffe starrer “How to Succeed in Business Without Really Trying” and movie adaptations “Sister Act” and “Priscilla Queen of the Desert,” for instance — all bowed toward the end of the season, which did see a rise in ticket sales to foreigners, according to a quarterly breakdown.Meanwhile, word of mouth remains the top influence on purchasing decisions, although for plays, which usually bring in an older, more traditional audience, reviews still hold a bit more sway than personal recommendations. For musicals, the top deciding factors were word of mouth and favorable knowledge of a musical’s score. The reported influence of advertisement in general continued to decline, with TV and the Internet repping the most-cited outlets for ads that turned auds’ heads. Broadway.com, a website owned by the same group that runs Rialto producer and presenter Broadway Across America, was the top source of info. The percentage of tickets bought more than a month in advance stayed steady at around 35%, but the ratio of ducats purchased one to four weeks prior to a show rose to 28% (vs. 22% the previous season). Trend is likely a relief to Main Stem producers, for whom advance sales have long provided a useful barometer of a production’s long-term B.O. outlook. Stats from the League’s report were compiled from about 5,750 returned surveys that were initially distributed to theatergoers at 27 productions at some 78 individual perfs. “Mormon,” “How to Succeed,” “Catch Me If You Can” “Jerusalem” and “The Phantom of the Opera” were among the shows where surveys were handed out.