condition mean min max ZT0-3 4.183848102000001 3.6360261680000003 4.731670036000001 ZT4-7 10.11243159275 7.673271633000001 12.5515915525 ZT8-11 19.877913632500004 17.468177150000002 22.287650115 ZT12-15 18.1534118575 17.128166049999997 19.178657665000003 ZT16-19 21.229939682500003 19.777297815 22.682581550000002 ZT20-23 26.6047434925 25.08114105 28.128345935