Hong Kong consumes very large amounts of Ketamine, MDMA and Cocaine. Admittedly, not so much meth or crack.
The actual number is probably higher, but doesn't compare to the USA with 24 million drug abusers out of a population of 331 million or 7.25%. https://www.drugabuse.gov/publications/drugfacts/nationwide-...
Where are you getting your information from that it is a problem in Hong Kong?