condition mean min max ZT0-3 15.100916 15.100916 15.100916 ZT4-7 17.494632 17.494632 17.494632 ZT8-11 20.532608 20.532608 20.532608 ZT12-15 21.852477 21.852477 21.852477 ZT16-19 21.446929500000003 21.446929500000003 21.446929500000003 ZT20-23 14.5577745 14.5577745 14.5577745