Hi There!
Very unlikely TR is going to recruit any foreign DEC at all, last intake was around 2013-2014. There is no shortage at the moment and no growth forecasted in the next 3-5 years. Plenty of local FO's are waiting in the pool for upgrade as soon as necessity arises. After 3-5 years all current MPL FO's who are green will meet requirements for upgrade if there is going to be any shortage of PIC. Majority of expats are leaving sooner or later, that is the long term trend, and TR is ready for this, as they take more and more local MPL/cadets and air force guys. The only reason why people are still around - is fixed roster, good lifestyle, around 12 hard days off per month. (commuting is available as well). 4 legs per day and layovers are once in 1 or 2 month.
Average per year is 900 hours = 206000 SGD (152000 USD) after tax (all in) for new joiner DEC. Seniority is a joke, after 4 years you will get another 400-500 USD per month and no further increase.