condition mean min max ZT0-3 17.059649999999998 17.059649999999998 17.059649999999998 ZT4-7 28.7881 28.7881 28.7881 ZT8-11 22.22515 22.22515 22.22515 ZT12-15 15.302299999999999 15.302299999999999 15.302299999999999 ZT16-19 17.588299999999997 17.588299999999997 17.588299999999997 ZT20-23 11.040949999999999 11.040949999999999 11.040949999999999