NEW YORK — The Broadway sales cume plummeted in Week 33 (Jan. 5-11) — which was only to be expected, after the closure of a whopping nine productions the previous frame.Most of the shows still on the boards also fell off from their strong holiday showings. Only a few productions bucked that trend, including “South Pacific” ($950,130), the tight-ticket tuner that rose by $9,000 and was one of the few shows to play to full houses. The revival of “Speed-the-Plow” ($334,428) also managed to rise slightly, with thesp Norbert Leo Butz playing his final week before William H. Macy takes over the lead role. (Butz and Macy were both brought in at the last minute, following the sudden departure of topliner Jeremy Piven.) “Billy Elliot” ($1,221,123) also remained robust, landing at No. 2 on the top 10. The musical was down about $140,000 — which is solid footing when compared with the major dips of hundreds of thousands of dollars each at other large-scale tuners, including “Mamma Mia!” ($853,192), “Shrek the Musical” ($849,651), “The Little Mermaid” ($736,172), “The Phantom of the Opera” ($733,230) and “Mary Poppins” ($684,799). Although “The Lion King” ($1,030,694) fell by more than $500,000 and “Wicked” ($1,365,879) was off by $400,000, receipts were still high enough to keep both shows in the millionaires’ club (and “Wicked” at No. 1). Three offerings closed Sunday, with “Gypsy” ($796,378) picking up sales in its final week, “All My Sons” ($705,418) holding steady and “Monty Python’s Spamalot” ($811,514) falling in the wake of holiday sales. A slew of shows remain on tap to open this spring to help fill in all those dark theaters, but the previous week only one joined the fray, with the first six previews of the Roundabout’s revival of “Hedda Gabler” (starring Mary-Louise Parker) bringing in $185,208. Total Rialto cume was down about $10 million to $15.8 million, just a bit higher than the $15.4 million tally logged during the same frame last year. The 17 musicals grossed $13,697,387 for 86.2% of the Broadway total, with an attendance of 174,892 at 91.3% capacity and average paid admission of $78.32. The six plays grossed $2,199,183 for 13.8% of the Broadway total, with an attendance of 31,542 at 68.5% capacity and average paid admission of $69.72. Average paid admission was $77.01 for all shows.