Prescaler was changed to PS1=9, PS2=30, PS3=10, PS4=30 before start Run 4865/23755/41532, the coda event rates were L~6.2k/R~5.5K and the dead time was smaller than 15% most of the time in the data taking; Prescaler was changed to PS1=8, PS2=27, PS3=9, PS4=28 before start Run 4866/23756/41533, the coda event rates were L~7k/R~6K and the dead time was smaller than 20% most of the time in the data taking;