condition mean min max ZT0-3 12.498046 12.498046 12.498046 ZT4-7 11.9170175 11.9170175 11.9170175 ZT8-11 11.726680000000002 11.726680000000002 11.726680000000002 ZT12-15 10.9677665 10.9677665 10.9677665 ZT16-19 11.902897 11.902897 11.902897 ZT20-23 11.2828615 11.2828615 11.2828615