condition mean min max ZT0-3 223.520976 223.520976 223.520976 ZT4-7 273.713091 273.713091 273.713091 ZT8-11 328.7665135 328.7665135 328.7665135 ZT12-15 314.96226850000005 314.96226850000005 314.96226850000005 ZT16-19 282.4450315 282.4450315 282.4450315 ZT20-23 323.307725 323.307725 323.307725