A population drain may be looming for Hong Kong, as the disillusioned residents of China’s special administrative region look for a way out from under Beijing’s creeping influence.

After months of protests calling for universal suffrage yielded no discernible results, thousands of Hong Kongers with “British National Overseas” status, which allows them to enter in the United Kingdom without a visa, are demanding that they be given British residency, according to AFP. A poll conducted by the Chinese University of Hong Kong in September, just as the protests were starting, found that one in five Hong Kongers was already considering emigrating.

Others are looking at destinations closer to home like Malaysia or South Korea, according to immigration consultants. The number of Hong Kong or Macau residents that moved to Taiwan during the first ten months of last year was about 6,400—almost double the previous year’s figure.

This wouldn’t be the first time that political turmoil triggered a wave of migration. Riots in 1967 kicked off a major outflow, and in the 1980s, ahead of the Hong Kong’s looming return to China, some 20,000 people were leaving every year. In 1989 that number ticked up to 40,000, and in 1990, after witnessing China’s military crackdown on democracy activists in Beijing, an estimated 62,000 Hong Kongers emigrated—about 1% of the population at the time.

By the time China regained control of Hong Kong in 1997, emigration was already on the decline, as those residents who feared living under Beijing’s rule had already found ways to leave.

Hong Kong Census and Statistics Department Hong Kong out migration between 1981 and 2001.

In the years since, emigration has fluctuated, continuing its post-handover decline before rebounding somewhat in the years following the financial crisis:

But a large number of residents may be biding their time. Approximately 400,000 Hong Kongers hold a British National Overseas status, though the statistics are obscured by the fact that some choose not to disclose that they have foreign right of abode status.

Many of the estimated 503,800 Hong Kong residents who left between 1987 and 1996, a little over 7% of the city’s current population, have subsequently returned, according to a government report.

“This means that there is a large number of Hong Kong residents who can readily re-emigrate as they already have acquired their foreign passports or permanent resident status elsewhere,” the report said.

Another spike in emigration, especially among the young, would be a major problem for Hong Kong, whose population is expected to grow to 8.7 million in 2031 even as its labor force shrinks. By 2031, 58% of the population (pdf, p. 12) will be made up of “economically inactive persons,” compared to 49% in 2001, according to government predictions.