condition mean min max ZT0-3 13.426589 13.426589 13.426589 ZT4-7 17.138085500000003 17.138085500000003 17.138085500000003 ZT8-11 21.900540999999997 21.900540999999997 21.900540999999997 ZT12-15 16.6293145 16.6293145 16.6293145 ZT16-19 17.014146 17.014146 17.014146 ZT20-23 17.972285499999998 17.972285499999998 17.972285499999998