Heathrow has revealed it was the only hub airport in Europe to see a reduction in passenger numbers in 2021, due to the UK’s tougher coronavirus travel rules. Just 19.4 million people travelled through the west London airport last year. That was down 12.3% on the previous 12 months, and represents the lowest annual total since 1972. The airport blamed its poor performance in comparison with European rivals on the UK’s tighter restrictions on international travel. Quarantine hotels remained in operation in the UK for several months after they were scrapped in most other European nations, putting many people off travelling abroad. Later in 2021, the UK was the only country in Europe requiring both a pre-departure test and post-arrival test for all arrivals, regardless of vaccination status. European hub airports which recorded a year-on-year increase in passengers in 2021 include Frankfurt (up 32.2%), Amsterdam’s Schiphol (up 22.0%) and Paris …