condition mean min max ZT0-3 11.541058 11.541058 11.541058 ZT4-7 11.5443695 11.5443695 11.5443695 ZT8-11 14.3556505 14.3556505 14.3556505 ZT12-15 13.103644500000001 13.103644500000001 13.103644500000001 ZT16-19 14.600733 14.600733 14.600733 ZT20-23 21.293864 21.293864 21.293864