condition mean min max ZT0-3 2.3708416666666667 1.39813 3.10266 ZT4-7 0.9190195000000001 0.9190195000000001 0.9190195000000001 ZT8-11 1.36478 1.36478 1.36478 ZT12-15 2.4595025 2.13523 2.7837750000000003 ZT16-19 2.3778699999999997 2.3778699999999997 2.3778699999999997 ZT20-23 3.6988849999999998 3.6988849999999998 3.6988849999999998