You do not need to build your own dataset or analyze an existing one to write your essay!
But, consulting statistical reports and data issued by reputable organizations may be useful in evaluating and supporting your hypothesis (depending of course on your topic). It might also help you think about how your hypothesis could be tested or expanded as a larger research project.
Statistical Databases - HKUST Library Subscribed
Hong Kong
Hong Kong Census and Statistics Department
China
Provincial statistics from are classed under HA4637 (e- versions available from 1989-)
Major City Statistics of China are classed under HA4638 (e- versions available from 1989-)
Or, you can also do a title search : 统计年鉴
Economic & Financial Data & Reports from International Organizations