More laborers in their twenties and foreign nationals are working on construction sites.
 
According to statistics released by the Construction Workers Mutual Aid Association on Tuesday, some four-point-six million laborers worked at least once on a construction site between 1997 and 2014.
 
Of those, four-point-28 million were members of the construction workers' mutual benefit fund for retirement. Some 320-thousand have left the construction industry after receiving retirement income from the fund.
 
Last year, around one-point-42 million laborers worked at least once on construction sites associated with the retirement fund.
 
Of those, the largest number, at almost 40 percent, were in their fifties, followed by those in their forties, sixties, thirties and twenties.
 
However, the number of people in their twenties who newly enter the construction workforce has increased from around 19 percent in 2012 to about 21 percent in 2013 and almost 22 percent last year.
 
From 1997 to 2014, the number of foreign nationals who joined the retirement fund was 338-thousand, or seven-point-three percent of the total.
 
The ratio of foreign construction workers who joined the retirement fund has increased from five-point-seven percent in 2011 to seven-point-nine percent last year.
 
Among foreign laborers, the percentage of those in their twenties has risen sharply since 2013, but the ratio of those in their fifties and sixties has fallen.