condition mean min max ZT0-3 0.7282626666666667 0.3707985 0.9149765000000001 ZT4-7 0.42504699999999995 0.42504699999999995 0.42504699999999995 ZT8-11 0.7157585 0.7157585 0.7157585 ZT12-15 2.32303 1.965185 2.6808750000000003 ZT16-19 1.73089 1.73089 1.73089 ZT20-23 1.556215 1.556215 1.556215