Question: When did the stratosphere in las vegas open?
qaPairs: question: When did the stratosphere officially open in las vegas open?
answer: April 30, 1996
question: When did the stratosphere open for a premiere in las vegas open?
answer: April 29, 1996
question: When did the stratosphere's SkyJump open in las vegas open?
answer: April 20, 2010
question: When did the stratosphere's Insanity open in las vegas open?
answer: 2005