condition mean min max ZT0-3 15.593441827166664 13.689420009333334 17.497463644999996 ZT4-7 12.908651677333335 10.283687324666667 15.533616030000001 ZT8-11 24.613387945 22.462875026666666 26.763900863333333 ZT12-15 7.786004284500001 4.323061905 11.248946664 ZT16-19 6.532918372999999 6.423845352 6.641991394 ZT20-23 3.9161477390000003 3.332907758 4.4993877200000005