A total of 1.3 billion square feet of property was standing empty in China at the end of July, "one square foot for every person in the country" as vacant properties increased 14% year-on-year. Unused residential property rose nearly 11% to 66 million square meters, the National Bureau of Statistics said Thursday. "This imbalance is hugely abnormal," Yi Xianrong, an economist at the Chinese Academy of Social Sciences, told the South China Morning Post. "This [vacancy rate] is purposefully done by developers to keep property prices high." He called on the government to increase rates in order to raise developers' investment costs in addition to the range of measures already introduced to cool the real estate market. State media reported Thursday that the China Banking Regulatory Commission increased to 35% the proportion of an investment that developers must raise in order to secure bank lending. Banks were also warned to check the credit records of those applying for personal home loans.