Noticed the attendance was a bit low for this one, 11,036 in the MGM Grand which can hold 16,800 according to wiki (and that seems to be without the chairs the UFC puts down on the floor).
You have to go back to the first two UFC events ever held in the MGM Grand (and 2002) to find a lower attendance for a UFC event in that stadium.
11,036 - UFC 173: Barao vs. Dillashaw (2014)
15,650 - UFC 168: Weidman vs. Silva 2 (2013)
14,856 - UFC 167: St-Pierre vs. Hendricks
12,964 - UFC 162: Silva vs. Weidman
12,380 - UFC 160: Velasquez vs. Bigfoot 2
13,561 - UFC 155: dos Santos vs. Velasquez 2 (2012)
15,104 - UFC 148: Silva vs. Sonnen 2
14,674 - UFC 146: dos Santos vs. Mir
13,793 - UFC 141: Lesnar vs. Overeem (2011)
13,109 - UFC 132: Cruz vs. Faber
12,753 - UFC 130: Rampage vs. Hamill
12,874 - UFC 125: Edgar vs. Maynard
12,740 - UFC 116: Lesner vs. Carwin (2010)
14,996 - UFC 114: Rampage vs. Evans
13,529 - UFC 108: Evans vs. Thiago Silva
12,606 - UFC 98: Evans vs. Machida (2009)
14,885 - UFC 94: St-Pierre vs. Penn 2
14,166 - UFC 92: Griffin vs. Evans (2008)
14,272 - UFC 91: Couture vs. Lesnar
14,773 - UFC 84: Penn vs. Sherk
14,728 - UFC 71: Liddell vs. Jackson (2007)
13,671 - UFC 66: Liddell vs. Ortiz (2006)
12,000 - UFC 56: Franklin vs. Quarry (2005)
13,520 - UFC 54: Liddell vs. Horn
14,562 - UFC 52: Couture vs. Liddell
12,100 - UFC 49: Belfort vs. Couture (2004)
13,770 - UFC 40: Ortiz vs. Shamrock (2002)
10,000 - UFC 36: Couture vs. Barnett
9,000 - UFC 34: Couture vs. Rizzo (2001)
