condition mean min max ZT0-3 4.5290675 4.4943800000000005 4.5637550000000005 ZT4-7 3.9488149999999997 3.9488149999999997 3.9488149999999997 ZT8-11 6.650045 6.650045 6.650045 ZT12-15 0 0 0 ZT16-19 5.6233450000000005 5.6233450000000005 5.6233450000000005 ZT20-23 5.01268 5.01268 5.01268