condition mean min max ZT0-3 9.1495 7.487395 10.04547 ZT4-7 7.62744 7.62744 7.62744 ZT8-11 4.936389999999999 4.936389999999999 4.936389999999999 ZT12-15 7.4866325 7.42556 7.547705 ZT16-19 7.407170000000001 7.407170000000001 7.407170000000001 ZT20-23 10.7286 10.7286 10.7286