In what year did Vietnamese beauties first marry into China?

From the mid-1980s to the late 1990s. Historically, Viet Nam was once the territory of China, and it was not until 968 that it officially broke away from China and began to establish its own country. The female population is far more than the male population, so it is a difficult problem for women to get married, so Vietnamese women like to marry in China. From the mid-1980s to the end of 1990s, it was the peak period for Vietnamese beauties to marry into China.