http://www.taxi.state.nv.us/FaresFees.htm says:
First 1/8th of a mile = $3.20
Each additional 1/8th = 0.25
Waiting time = $22.00 per hour
McCarran Airport pickup fee = $1.20
Guess that will make it 0.275 per eighth now?
So it's a 10% increase in the per-mile rate.