condition mean min max ZT0-3 44.987975000000006 42.3986 47.57735 ZT4-7 17.59575 17.59575 17.59575 ZT8-11 10.067074999999999 10.067074999999999 10.067074999999999 ZT12-15 0 0 0 ZT16-19 23.53505 23.53505 23.53505 ZT20-23 22.2578 22.2578 22.2578