Chart of the Day: See the rapid slide of Singapore's working-age population growth

Growth will hover at less than 0.5% by 2020.

The rapid decline in Singapore's labour force will take a heavy toll on the city-state's growth in coming years, according to a report by BMI Research.

BMI Research expects real GDP growth to average 2.5% per annum through 2020, compared to 5.4% from 2006-2015.

"On top of the aforementioned headwinds, Singapore will also have to grapple with a significant decline in the growth rate of its labour force, which is to some extent another side effect of tighter immigration rules. This will cap growth potential, and make the economy progressively more reliant upon productivity growth in order to achieve a consistent rate of expansion," said BMI Research.