condition mean min max ZT0-3 2.03957 2.03957 2.03957 ZT4-7 11.931295 11.931295 11.931295 ZT8-11 5.18665 5.18665 5.18665 ZT12-15 2.364885 2.364885 2.364885 ZT16-19 14.588650000000001 14.588650000000001 14.588650000000001 ZT20-23 8.250255 8.250255 8.250255