condition mean min max ZT0-3 12.102627 12.102627 12.102627 ZT4-7 10.603238000000001 10.603238000000001 10.603238000000001 ZT8-11 9.2693285 9.2693285 9.2693285 ZT12-15 10.260686 10.260686 10.260686 ZT16-19 11.913160000000001 11.913160000000001 11.913160000000001 ZT20-23 9.798684000000002 9.798684000000002 9.798684000000002