You might not know it from the cumulative figures, but Broadway sales took baby-steps toward a rebound last week, with nearly every show on the boards posting gains.Looking at the overall totals, B.O. was up less than $100,000 to $17.2 million for 22 shows on the boards. But that’s because all the week’s upticks were countered by the loss of “Porgy and Bess,” which, after shuttering Sept. 23, was no longer around to throw coin into the pot. Nonetheless, almost every inidividual production improved compared to the previous frame, which saw sales slump in a September sesh that wasn’t boosted by the 2-for-1 ticket deals of the recently-ended Broadway Week. Biggest rise of the week came at “Bring It On” ($485,269), up 31% in a bump that suggests the show might be gaining a bit of autumn momentum now that we’re past the back-to-school distractions of early September. The recently opened “Chapin” ($498,568) also gathered steam with a rise of about 12%; spring opener “Newsies” ($848,585), longrunner “Mamma Mia!” ($813,955) and play “War Horse” ($604,824), closing in January, also climbed by about the same percentage. In the Top 10, “Jersey Boys” ($1,052,914) and “Once” ($1,007,256) each stepped up by enough to restore membership in the millionaires’ club. That means seven productions topped the $1 million mark in weekly sales — a strong showing for a September frame, and another mark of the growing divide between the Street’s top sellers and the rest of the pack, with little middle ground. At the very top of the list, “The Book of Mormon” ($1,636,331) remained king of the hill, making a habit out of besting more frequent top dogs “The Lion King” ($1,600,129) and “Wicked” ($1,536,124). The latter two, however, are on their way back up and looked poised to take “Mormon” down a notch or two sometime in the coming weeks. Joining the fray last week was “Who’s Afraid of Virginia Woolf?” ($190,160 for five previews), which managed to beat full weeks of nonprofit revivals of “Cyrano de Bergerac” ($169,950) and “An Enemy of the People” ($165,381) — although “Enemy” was off because it had to accommodate press previews and opening night. Paul Rudd and Michael Shannon starrer “Grace” ($440,352) reported the biggest decline of the frame, but the show was only off about $25,000 and besides, it played just seven perfs (rather than the usual eight) and accommodated a number of comped press seats as well. Taking all that into account, sales looked pretty healthy as the show heads toward its Oct. 4 opening. Overall Rialto attendance inched up by about 1,000 to 184,210. That’s way down from the 208,000 posted during the same week in 2011, but that frame benefitted from the aforementioned Broadway Week initiative, which in 2011 ran through the end of September.