condition mean min max ZT0-3 181.698557 181.698557 181.698557 ZT4-7 186.512889 186.512889 186.512889 ZT8-11 247.0924865 247.0924865 247.0924865 ZT12-15 214.63644699999998 214.63644699999998 214.63644699999998 ZT16-19 184.48576300000002 184.48576300000002 184.48576300000002 ZT20-23 147.818374 147.818374 147.818374