condition mean min max ZT0-3 4.825503333333334 3.98072 5.250535 ZT4-7 3.8476299999999997 3.8476299999999997 3.8476299999999997 ZT8-11 4.100315 4.100315 4.100315 ZT12-15 4.2225825 4.079845000000001 4.36532 ZT16-19 4.9857 4.9857 4.9857 ZT20-23 6.4525500000000005 6.4525500000000005 6.4525500000000005