condition mean min max ZT0-3 1.5337582205 1.217096615 1.850419826 ZT4-7 5.0040437465 3.1766629155 6.8314245775 ZT8-11 9.90921842075 9.5649410415 10.2534958 ZT12-15 3.25524050725 1.604156835 4.906324179499999 ZT16-19 0.8636375485 0.7857845754999999 0.9414905215 ZT20-23 0.47419318624999995 0.4081179565 0.540268416