Gross gaming revenue of Macau casinos sputtered to 12.1 percent in May after having a stellar April results, according to Macau’s Gaming Inspection and Coordination Bureau.

Financial record showed that Macau casino raked in MOP25.49 billion ($3.15 billion) in May, higher than the MOP22.74 billion ($2.82 billion) it registered during the same period last year. However, the casino GGR for May is lower than the 27.6 percent year-on-year growth it posted in April.

The May results were also much lower than the 16 percent to 17 percent average growth estimates of brokerage firms and gambling analysts. The latest figures brought Macau’s five-month casino GGR tally to nearly MOP127.73 billion ($15.83 billion), a year-on-year expansion of 20.1 percent.

International brokerage Union Gaming noted the May GGR slowdown was triggered by the fall of mass market number, which was caused by the mid-month mainland police busts against currency exchange shops at the Gongbei border.