NEW YORK — Broadway grosses inched upward during Week. 18 (Sept. 30-Oct. 6), rising by 3.5% to $12,893,384. Attendance of 203,635 was up by 2.5%.The roster was almost evenly divided between gainers and losers for the frame. With strong reviews for its new leads, Sally Field and Bill Irwin, “The Goat” had its best week to date at the Golden, notching a rise of $14,288 and earning $221,956. “Thoroughly Modern Millie” took the biggest hit, sliding by $75,372 to $771,140. The Billy Joel-Twyla Tharp dance musical “Movin’ Out” joined the roster for a full week of previews. Show grossed a hefty $645,921 of a potential $810,163 and bypassing the TKTS booth for weekend perfs. The 20 musicals grossed $11,396,273 for 88.4% of the Broadway total. Attendance of 174,153 represented 79.5% of capacity. The six plays grossed $1,497,111 for 11.6% of the Broadway total, with attendance of 29,482 at 72.5% of capacity. Average ticket prices were $65.44 for musicals, $50.78 for plays and $61.13 for all shows.