Winter, believe it or not, has been kind to Broadway this year.Sure, last week’s box office numbers may not have given legiters much to get excited about, but for a mid-February frame, it wasn’t so bad. And measuring from the start of the calendar year, the current annum is well ahead of 2011 both in terms of sales and attendance. According to numbers put together by the Broadway League, this year’s B.O. cume hit $112.3 million vs. the $87.6 million logged for the same weeks in 2011. Attendance reached 1.3 million, compared to the 1 million theatergoers who turned out during the same window last year. A number of factors contribute to the uptick, not least of which is the higher number of productions running this year than over the same six weeks in 2011. There are also Street-wide promotional deals, under the banners Broadway Week (which ended Feb. 4) and Kids’ Night on Broadway (Feb. 5-9), helping to heat up winter biz, and on top of that, the unseasonably warm winter hasn’t yielded a single blizzard to scare off auds. In a week when some shows were up and others were down — and none of the fluctuations were attention-grabbing — the biggest news of the frame was possibly the 10,000th performance of “The Phantom of Opera” ($604,378) on Feb. 11. The week’s tally was down a bit from the prior sesh in part because half the inventory at that landmark perf on Saturday was donated to an Actors Fund charity event. Also down was “Porgy and Bess” ($818,346), in a dip possibly attributable to the four-show absence of above-the-title thesp Norm Lewis. A far more worrying decline was posted at “Sister Act” ($426,152), which saw attendance slide below 48%, as well as at soon-to-close play “Stick Fly” ($196,337), another show that played to less than half of capacity. Among those reporting gains over the prior week was “Wicked” ($1,508,501), which reclaimed the top spot on the charts ahead of last week’s leader, “The Book of Mormon.” The latter, however, still did just fine, breaking yet another house record at the O’Neill Theater with a weekly tally of $1,485,740. “Spider-Man: Turn of the Dark:” ($1,378,970) and “The Lion King” ($1,349,837) rounded out the frame’s millionaires’ club. Among the other productions to see a sales bump were the ones most likely to have gotten a boost from the Kids’ Night campaign, including youngster-friendly “Mary Poppins” ($667,272) and “How to Succeed in Business Without Really Trying” ($656,165), whose star, Nick Jonas, was promoted as the Kids’ Night ambassador. Overall sales climbed about $600,000 to $15.6 million. That’s higher than the $15.1 million posted during the same frame last year, but last week’s attendance of 177,602 was a bit below the 179,000 from 2011. Joining the fray last week was the commercial transfer of last fall’s nonprofit staging of “Venus in Fur” ($346,117), reporting solid numbers for a play that’s technically still in previews ahead of a Feb. 29 re-opening.