condition mean min max ZT0-3 1.6900595 1.0158435 2.92699 ZT4-7 1.8934250000000001 1.8934250000000001 1.8934250000000001 ZT8-11 0.7593915 0.7593915 0.7593915 ZT12-15 1.5850400000000002 1.1995650000000002 1.970515 ZT16-19 1.74267 1.74267 1.74267 ZT20-23 1.247791 1.247791 1.247791