condition mean min max ZT0-3 8.21775086325 3.389883655 13.0456180715 ZT4-7 21.159543992499998 19.086018485 23.2330695 ZT8-11 41.0127321725 30.37681093 51.648653415 ZT12-15 41.97048435 31.04259487 52.89837383 ZT16-19 20.055015827 15.169494509 24.940537145 ZT20-23 7.64543247925 6.3940939285 8.89677103