New Delhi, December 21: Commercial office real estate flourished and remained the top-ranking real estate asset class in 2019, while residential continued to struggle due to funding crunch, according to a recent survey. The data published by Anarock reveals that towards the end of 2019, more than 72 per cent of the total loans advanced to Grade A builders (around $65 bn) are safe and stress-free, while Grade B and C developers collectively accounted for USD 28 bn of the total loan advances.