As of 2012, Singapore total fertility rate (TFR) is 1.20 children born per woman, which represents a sub-replacement fertility rate and is one of the lowest in the world. Ethnic Chinese had a ferlility of 1.07 in 2004 (1.65 in 1990), while Malays had a TFR of 2.10 (2.69 in 1990). Both figures declined further in 2006. TFR for Indians was 1.30 in 2004 and 1.89 in 1990.  The Singapore government has launched several highly publicised attempts to raise the fertility rate and increase awareness of the negative effects of an aging population, the elderly (65 and above) had constituted 9.9% of its population in 2012; this proportion is still significantly lower than that of many other developed nations, such as the United States (12%) and Japan (21.2%) .
Question: How many percentage points higher is the aging population of the United States compared to Singapore?
Answer: 2.1