In March, passenger air travel plummeted to levels not seen since 2006, according to the International Air Transport Association.

Passenger airlines responded by canceling flights and parking planes in an attempt to reduce costs as revenue took a nosedive. Those passenger planes didn't just carry people, though.

A significant portion of airfreight is typically carried in the belly of aircraft — 40-50% according to estimates from various industry players. So, when passenger planes were grounded, it resulted in a nearly 44% YoY reduction of cargo capacity.

Companies like Atlas Air, FedEx and UPS with dedicated freighter fleets saw their demand swell as shippers looked to secure capacity and governments scrambled to quickly transport personal protective equipment. Passenger airlines also began flying cargo-only flights as it became the only line item to see revenue growth.

Read the articles below to understand how it all unfolded and the impact it had on shippers throughout the year.