condition mean min max ZT0-3 11.248662573 8.499559326 13.99776582 ZT4-7 8.78338401625 8.066920054 9.4998479785 ZT8-11 11.613864743499999 9.562859721999999 13.664869764999999 ZT12-15 9.768882406500001 9.064861432 10.472903381 ZT16-19 6.4926506682500005 5.911007651 7.074293685500001 ZT20-23 10.5605606585 9.999104452000001 11.122016864999999