condition mean min max ZT0-3 12.500663 12.500663 12.500663 ZT4-7 13.230572500000001 13.230572500000001 13.230572500000001 ZT8-11 12.6179935 12.6179935 12.6179935 ZT12-15 13.2504995 13.2504995 13.2504995 ZT16-19 12.826487 12.826487 12.826487 ZT20-23 14.674812 14.674812 14.674812