condition mean min max ZT0-3 12.975425000000001 12.644100000000002 13.306750000000001 ZT4-7 14.27045 14.27045 14.27045 ZT8-11 18.0952 18.0952 18.0952 ZT12-15 0 0 0 ZT16-19 20.1524 20.1524 20.1524 ZT20-23 15.13245 15.13245 15.13245