condition mean min max ZT0-3 15.8551 12.6007 19.8363 ZT4-7 20.275100000000002 20.275100000000002 20.275100000000002 ZT8-11 15.60135 15.60135 15.60135 ZT12-15 18.182375 17.74845 18.616300000000003 ZT16-19 16.0749 16.0749 16.0749 ZT20-23 18.39345 18.39345 18.39345