singaporean here
most of them are indeed young, in the 20-40 age range. fun fact, by singapore law they cannot apply for a work permit (and hence work in singapore) if they are >50 yrs old.
and when it comes to numbers, to generalise all Asian countries as ones to fudge and report false numbers is actually ridiculous and borderline racist. if u know anything at all, singapore's government is one of the least corrupt in the world.
in summary, majority of infections are foreign workers, young and in good health. aka the group least susceptible to covid 19. along with excellent healthcare system, it's no surprise the no. of deaths is so low.