There were 26,768 non-local students enrolled at the city’s international schools in the current academic year, comprising 66 percent of the total intake, according to the education bureau. That’s down from 30,499, and 74 percent, respectively, in 2019-2020.

There’s no easy way to ascertain how many expats fled the finance hub during the Covid era, when the city was closed off to the world. The top US official in Hong Kong said in January he estimated 20 percent of Americans in the city left in the last two years. An economic slump and concern over Beijing’s greater control over Hong Kong worsened the exodus.

Officials classify local students as permanent residents who possess only a Hong Kong passport.

The decline in non-local students may become a problem to operators of international schools if it continues. Under government rules, non-local students must account for an average 70 percent of the total.

Hong Kong has 54 international schools, including 22 run by the English Schools Foundation. Earlier this month, the education bureau cautioned ESF and three other foreign educational institutions for failing to admit the required number of non-local students for two consecutive years, Hong Kong based Chinese media reported.

Authorities will take follow-up actions, including terminating agreements with international schools if they fail to meet the rules, the education bureau said at a Legislative Council meeting on Monday. Officials said the attrition rate may be higher than usual because of the pandemic and schools have provided feedback about operational difficulties.