condition mean min max ZT0-3 3.488120337 3.271949597 3.7042910769999997 ZT4-7 5.20246442375 4.4448907645 5.960038083000001 ZT8-11 5.629782824 5.136395572 6.123170076000001 ZT12-15 6.225040558750001 5.7711163395 6.678964778000001 ZT16-19 8.6142454395 7.605682574 9.622808305 ZT20-23 13.605750355 12.447948695000001 14.763552014999998