condition mean min max ZT0-3 7.293704999999999 7.293704999999999 7.293704999999999 ZT4-7 15.945599999999999 15.945599999999999 15.945599999999999 ZT8-11 7.6517 7.6517 7.6517 ZT12-15 6.074165000000001 6.074165000000001 6.074165000000001 ZT16-19 6.22291 6.22291 6.22291 ZT20-23 6.46172 6.46172 6.46172