Found this article from TODAY newspaper interesting. In the short article, it brings up a few points.
Point 1: Number of international students has increased 25% over the last 4 years.
Significance: Increase in international students = increase in expat families. Singapore remains an attractive location for companies. Additionally, the expats coming over should be relatively high-level for the companies to relocate the entire family. Since companies are unlikely to purchase real estate simply to house their expats, this should continue provide support for the rental market.