For easy reference in future, we carry below the statistics relating to employed expatriates/workers for the years 2012 to 2016, extracted from the Ministry of Manpower website on 24 Feb 2017.
Equivalent data for the years 2007 to 2012 can be seen at this page.
Percentage-wise, these are the figures:
The next table shows quite clearly how the growth in foreigner numbers have been levelling off in recent years. This is a result of deliberate policy of controlling immigration. The levelling off however, is not across-the-board. Among “foreign workers” — a term usually used to mean work permit holders — construction numbers are almost flat, whilst domestic workers continue to increase.