But in recent years, some of the country's 25 million inhabitants have travelled to China, usually to work illicitly with the aim of returning to their families.
When shop managers left, usually to work elsewhere in the wine trade, store sales fell and the company's response was to cut staff, causing a vicious circle.
Usually, to work out which species a sample came from, researchers copy a particular section of DNA and then compare the sequence to a reference library.
The result is something like the Amish rumspringa: young people often leave, usually to work in Alberta, but a surprising number end up coming back.
When they venture out, it is usually to work, trudging through the rubble-strewn alleyways wrapped head to toe in thick black cloth, often lugging something on their back, the equatorial sun burning down on them.
When we were no longer subject to the tyranny of school holidays, I started to go to a rented cottage on the west coast of Scotland in August, usually to work on a book.
