Global business jet deliveries dropped 20.4 percent to 644 aircraft in 2020 as the COVID-19 pandemic weighed on production earlier in the year, the General Aviation Manufacturers Association (GAMA) said on Wednesday.

Jet makers like General Dynamics Corp’s Gulfstream, Bombardier Inc and Textron saw a rebound in deliveries during the last three months of 2020, but the industry does not expect a full recovery to pre-pandemic levels this year.

Business aviation has recovered faster from the pandemic than commercial airlines, helped by demand from first-time buyers, leisure travel, and wealthy individuals who are looking for private aircraft during COVID-19 because they seat fewer passengers.

“Behaviors are changing. The buyers are no longer asking the questions that they would have normally asked about the aircraft in terms of performance,” said Mike Amalfitano, chief executive of Embraer SA’s executive jets division, during an online briefing on the GAMA data.

“They’re focused on how clean it is. They’re focused on the air quality.”

Travel and manufacturing restrictions weighed on industry deliveries, while corporate demand has remained sluggish.

Parent company Signature Aviation, a private jet services firm, backed a joint offer earlier this month from former Gatwick owner GIP, Blackstone Group Inc and Bill Gates’ investment vehicle Cascade valuing it at $4.73 billion, in a deal that analysts say shows the resilience of the business aviation market.