condition mean min max ZT0-3 27.461436 27.461436 27.461436 ZT4-7 28.613479500000004 28.613479500000004 28.613479500000004 ZT8-11 20.5377285 20.5377285 20.5377285 ZT12-15 17.265751 17.265751 17.265751 ZT16-19 26.550673000000003 26.550673000000003 26.550673000000003 ZT20-23 55.4936005 55.4936005 55.4936005