condition mean min max ZT0-3 10.414681 10.414681 10.414681 ZT4-7 12.147571 12.147571 12.147571 ZT8-11 11.732700999999999 11.732700999999999 11.732700999999999 ZT12-15 11.531772 11.531772 11.531772 ZT16-19 12.080871 12.080871 12.080871 ZT20-23 11.738745999999999 11.738745999999999 11.738745999999999