PHL Airport hasn’t seen numbers like this since 2008

“Thanks to added airlift out of Philadelphia, the region’s airport last reached sky-high numbers it hasn’t seen in over a decade. Nearly 31.7 million passengers made their way through the Philadelphia International Airport in 2018, up over 7 percent year over year, according to airport officials.”
The substantial growth is attributed to new air service, including flights to 27 destinations from a number of different airlines. The new flights included both domestic and international routes and were through American Airlines – Philadelphia’s dominant airline.
Low-cost airlines such as Spirit and Frontier also expanded their network outside of PHL – with totals of 12 and 31 destinations, respectively.