condition mean min max ZT0-3 14.811499999999999 13.62815 15.99485 ZT4-7 7.44749 7.44749 7.44749 ZT8-11 11.15475 11.15475 11.15475 ZT12-15 0 0 0 ZT16-19 14.72035 14.72035 14.72035 ZT20-23 16.073549999999997 16.073549999999997 16.073549999999997