MUMBAI: India's domestic air traffic crossed 10 million for the first time in May as a growing economy and cheap fares spurred demand for travel.India'a carriers flew 10.2 million passengers in May, up 17% on year.For the period Jan-May Indian carriers ferried 47 million passengers, up 18% on year. SpiceJet topped the seat occupancy list averaging load factors of 94% for May, while IndiGo had the highest percentage--85%-- of its flights on time.