The percentage of occupied jobs in the employed population requiring advanced technological skills. In theory, jobs that are and are not occupied (vacancies) should be counted. However, the figures on vacancies are quite negligible. More importantly, the Supplementary Survey of Job Vacancies used a different classification of occupation from the current one before 1993. To maintain consistency over time, only jobs that are occupied are counted. Jobs requiring advanced managerial and technological skills refer to managers and administrators, professionals and associate professionals. The Census and Statistics Department has noted that from 1993 onwards, the occupational classification used in the General Household Survey basically follows the major groups of the “International Standard Classification of Occupations (1988)” with local adaptation for Hong Kong. There are significant differences, according to the Department, between this classification scheme and the one adopted for years prior to 1993, and therefore no comparison can be made with earlier years.