condition mean min max ZT0-3 23.762493 23.762493 23.762493 ZT4-7 15.671121500000002 15.671121500000002 15.671121500000002 ZT8-11 14.3940345 14.3940345 14.3940345 ZT12-15 14.214390999999999 14.214390999999999 14.214390999999999 ZT16-19 13.4009295 13.4009295 13.4009295 ZT20-23 15.3723565 15.3723565 15.3723565