condition mean min max ZT0-3 248.164865 248.164865 248.164865 ZT4-7 227.80375099999998 227.80375099999998 227.80375099999998 ZT8-11 242.9373325 242.9373325 242.9373325 ZT12-15 271.74312999999995 271.74312999999995 271.74312999999995 ZT16-19 384.915176 384.915176 384.915176 ZT20-23 414.79425649999996 414.79425649999996 414.79425649999996