There are a couple of standout observations to make about the Broadway box office last week. This first is that the unlikely pair of Cinderella and Barry Manilow have something in common. The second: It’s good to be closing — or at it was last week.The Rialto cume for the week ended Feb. 3 downshifted almost across the board, except for a couple of new outings and two other titles that are on their way out the door. Among the productions to resist the Rialto-wide trend was “Cinderella” ($950,035), proving that the prior week’s head-turning sales for its first three previews weren’t a fluke. The musical continues to show commercial promise, playing its first full frame of eight shows and coming within a stone’s throw of the millionaires’ club, which was led last week by “The Book of Mormon” ($1,635,426). It’s hard to prove that “Cinderella” siphoned away sales from “Annie” — a tuner that would seem to be vying for the same girl-centric demo of family auds — but it seems like something to keep an eye on in the coming weeks. “Annie” posted the biggest decline of the frame, sliding 20% (or more than $200,000) to $821,246. In any event, “Cinderella” and Manilow were two of a kind last week, since it was “Manilow on Broadway” ($796,714 for five perfs) that was the other robust new show of the winter, with Manilow back to performing in his concert stint after a week that saw him laid low by bronchitis. Two of the older shows to rise last week both had imminent closings on the horizon. Jessica Chastain topliner “The Heiress” ($673,937), boosted by the Hollywood awards-season spotlight on its star, posted its best tally ever as it headed toward its Feb. 9 closing. Meanwhile, “Mary Poppins” ($708,355) also rose, though less notably, as the production moves closer to its March 3 finale. “The Phantom of the Opera” ($748,949) picked up as well, but that was to be expected after the prior frame, which was down thanks to the show’s heavily comped 25th anniversary perf. Overall Broadway cume slipped around $500,000 to $16.6 million for 22 shows on the boards. Attendance dipped, just barely, to 180,859, or around 82% of overall capacity, a decent tally likely pumped by the current Broadway Week ticket initiative that aims to keep up traffic in slow winter frames. On the Main Stem calendar, it’s usually right around now — in the late January/early February seshes — that sales dwindle to their lowest point. On the bright side, the annual climb back up will likely come later this month.