condition mean min max ZT0-3 6.534125 6.534125 6.534125 ZT4-7 6.0878 6.0878 6.0878 ZT8-11 4.982575 4.982575 4.982575 ZT12-15 6.559245 6.559245 6.559245 ZT16-19 7.815775 7.815775 7.815775 ZT20-23 7.102264999999999 7.102264999999999 7.102264999999999