12. Our customers are primarily female patients who receive medical care and related services at our hospitals. Our target customers are patients that generally have an annual household income of above RMB200,000. No individual patient accounted for more than 5% of our total revenue for the three years ended December 31, 2012, 2013 and 2014, respectively. Our five largest customers during the Track Record Period were corporate customers of our supply of pharmaceuticals and medical devices business, who in aggregate contributed to less than 5% of our revenue during the Track Record Period.devices purchased, respectively.