condition mean min max ZT0-3 7.215625 6.1321449999999995 8.299105 ZT4-7 5.1181350000000005 5.1181350000000005 5.1181350000000005 ZT8-11 3.9909350000000003 3.9909350000000003 3.9909350000000003 ZT12-15 0 0 0 ZT16-19 5.5058 5.5058 5.5058 ZT20-23 8.40091 8.40091 8.40091