condition mean min max ZT0-3 6.057385 5.672275000000001 6.442495 ZT4-7 5.726795 5.726795 5.726795 ZT8-11 5.43793 5.43793 5.43793 ZT12-15 0 0 0 ZT16-19 6.380850000000001 6.380850000000001 6.380850000000001 ZT20-23 6.7907399999999996 6.7907399999999996 6.7907399999999996