An important factor in the crappy grosses that hasn't been mentioned:
From Thursday through Sunday, all the tourists in town were either participating in or connected to the NYC Marathon. They were focused on carbs and running, not going to the theater. The hotels were full, but not with the typical NYC visitors. Since about 60% or more of audiences are traditionally out-of-towners, the drop in attendence makes sense.
2016 These Paper Bullets (1/02) Our Mother's Brief Affair (1/06), Dragon Boat Racing (1/08), Howard - reading (1/28), Shear Madness (2/10), Fun Home (2/17), Women Without Men (2/18), Trip Of Love (2/21), The First Gentleman -reading (2/22), Southern Comfort (2/23), The Robber Bridegroom (2/24), She Loves Me (3/11), Shuffle Along (4/12), Shear Madness (4/14), Dear Evan Hansen (4/16), American Psycho (4/23), Tuck Everlasting (5/10), Indian Summer (5/15), Peer Gynt (5/18), Broadway's Rising Stars (7/11), Trip of Love (7/27), CATS (7/31), The Layover (8/17), An Act Of God (8/31), The Curious Incident of the Dog in the Night-Time (8/24), Heisenberg (10/12), Fiddler On The Roof (11/02), Othello (11/23), Dear Evan Hansen (11/26), Les Liaisons Dangereuses (12/21) 2017 In Transit (2/01), Groundhog Day (4/04), Ring Twice For Miranda (4/07), Church And State (4/10), The Lucky One (4/19), Ernest Shackleton Loves Me (5/16), Building The Wall (5/19), Indecent (6/01), Six Degrees of Separation (6/09), Marvin's Room (6/28), A Doll's House Pt 2 (7/25) Curvy Widow (8/01)