Airlines were the top performing group Monday as oil prices slumped more than 4%. And while a few former leaders like Southwest (LUV) and Spirit Airlines (SAVE) have gotten into trouble, the group still ranks a respectable No. 24 in Tuesday’s paper. SkyWest (SKYW), new to the Spotlight screen, is a commercial airline headquartered in St. George, Utah, that provides more than 3,500 daily scheduled flights in North America.