condition mean min max ZT0-3 238.747172 238.747172 238.747172 ZT4-7 268.3028275 268.3028275 268.3028275 ZT8-11 325.59155499999997 325.59155499999997 325.59155499999997 ZT12-15 284.32100749999995 284.32100749999995 284.32100749999995 ZT16-19 253.1154405 253.1154405 253.1154405 ZT20-23 227.15165000000002 227.15165000000002 227.15165000000002