New York City has a high degree of income disparity as indicated by its Gini Coefficient of 0.5 for the city overall and 0.6 for Manhattan. The disparity is driven by wage growth in high-income brackets, while wages have stagnated for middle and lower-income brackets. In the first quarter of 2014, the average weekly wage in New York County (Manhattan) was $2,749, representing the highest total among large counties in the United States. In 2013, New York City had the highest number of billionaires of any city in the world, higher than the next five U.S. cities combined, including former Mayor Michael R. Bloomberg. New York also had the highest density of millionaires per capita among major U.S. cities in 2014, at 4.6% of residents. Lower Manhattan has been experiencing a baby boom, with the area south of Canal Street witnessing 1,086 births in 2010, 12% greater than 2009 and over twice the number born in 2001.