China’s aviation industry lost a combined 84.3 billion yuan ($12.5 billion) last year, as the country kept its borders closed to keep out Covid-19. A rebound in domestic travel to pre-pandemic levels helped narrow total losses from 97.4 billion yuan in 2020, China’s aviation regulator said Thursday. Sales by airlines and airports rose 22% last year, but that was nowhere near enough to surmount the loss of business from international travel. Airlines are again doing it tough this year after the financial hub of Shanghai was locked down for six weeks and restrictions imposed in a raft of cities to stamp out Covid flareups. All of the big-three listed airlines posted wider first-quarter losses.