condition mean min max ZT0-3 11.216636634499999 10.258250809 12.17502246 ZT4-7 7.3655589077500006 7.1781223485000005 7.552995467000001 ZT8-11 7.633441025250001 7.1624473515 8.104434699 ZT12-15 8.9766812315 7.841586208000001 10.111776255 ZT16-19 12.27149730475 10.0419805695 14.50101404 ZT20-23 21.422034049999997 20.450092544999997 22.393975554999997