condition mean min max ZT0-3 18.569699999999997 18.569699999999997 18.569699999999997 ZT4-7 17.87845 17.87845 17.87845 ZT8-11 13.7578 13.7578 13.7578 ZT12-15 15.499600000000001 15.499600000000001 15.499600000000001 ZT16-19 14.879750000000001 14.879750000000001 14.879750000000001 ZT20-23 17.07625 17.07625 17.07625