Find a missing number

Two men are sitting drinking at a bar at the top of the Empire State Building when the first man turns to the other and says, "You know, last week I discovered that if you jump from the top of this building, by the time you fall to the 10th floor, the winds around the building are so intense that they carry you around the building and back into the window."

The bartender just shakes his head in disapproval while wiping the bar.

The second guy says, "What are you a nut? There is no way that could happen."

"No, it's true," said the first man, let me prove it to you." He gets up from the bar, jumps over the balcony, and plummets to the street below. When he passes the 10th floor, the high wind whips him around the building and back into the 10th floor window and he takes the elevator back up to the bar.

He met the second man, who looked quite astonished. "You know, I saw that with my own eyes, but that must have been a one time fluke."

"No, I'll prove it again," says the first man as he jumps. Again just as he is hurling toward the street, the 10th floor wind gently carries him around the building and into the window.

Once upstairs he urges his fellow drinker to try it. "Well, what the hey," the second guy says, "it works, I'll try it!" He jumps over the balcony plunges downward, passes the 11th, 10th, 9th, 8th floors ...and hits the sidewalk with a 'splat.'

Back upstairs the Bartender turns to the other drinker, saying "You know, Superman, sometimes you can be a real jerk."