condition mean min max ZT0-3 4.812595 4.06379 5.5614 ZT4-7 7.1676649999999995 7.1676649999999995 7.1676649999999995 ZT8-11 10.33275 10.33275 10.33275 ZT12-15 0 0 0 ZT16-19 8.498674999999999 8.498674999999999 8.498674999999999 ZT20-23 7.904120000000001 7.904120000000001 7.904120000000001