condition mean min max ZT0-3 6.0771222475 2.9885589550000002 9.16568554 ZT4-7 16.965441752666667 13.352623575333334 20.578259929999998 ZT8-11 17.03641528016667 12.303792654666667 21.769037905666668 ZT12-15 17.085896928333334 16.103813546666668 18.06798031 ZT16-19 6.077856706333334 5.829021701 6.326691711666666 ZT20-23 5.1417028049999995 4.842823531 5.440582079