condition mean min max ZT0-3 19.045454 19.045454 19.045454 ZT4-7 38.7072615 38.7072615 38.7072615 ZT8-11 19.427095 19.427095 19.427095 ZT12-15 19.513528 19.513528 19.513528 ZT16-19 20.574055 20.574055 20.574055 ZT20-23 17.2555775 17.2555775 17.2555775