Residential rents in Singapore rose to a three-year high in 2019, with prices boosted by strong overseas demand that signals the city state’s continuing appeal among expatriates.Rents climbed 1.4% last year, according to real estate agency OrangeTee & Tie Pte, using data from the Urban Redevelopment Authority.The number of leases signed reached a decade-high 93,920 units last year, said Christine Sun, head of research and consultancy at OrangeTee & Tie.Demand for rental flats in Singapore…