condition mean min max ZT0-3 1.0525776666666666 1.032335 1.081851 ZT4-7 1.3051535 1.3051535 1.3051535 ZT8-11 1.59635 1.59635 1.59635 ZT12-15 1.31104625 0.7336075 1.888485 ZT16-19 0.9289285 0.9289285 0.9289285 ZT20-23 0.454756 0.454756 0.454756