Please provide more information about this set of policy measures and indicate what has been done to identify the causes of this phenomenon and to determine the profile of the women (age, ethnic origin and so forth) who engage in prostitution.
请提供有关这一套政策措施的更多资料，并说明为查明造成这种现象的原因以及查明从事卖淫工作的妇女情况（年龄、种族等）所进行的工作。