condition mean min max ZT0-3 203.5 203.5 203.5 ZT4-7 265.7 265.7 265.7 ZT8-11 409.75 409.75 409.75 ZT12-15 546.0 546.0 546.0 ZT16-19 487.75 487.75 487.75 ZT20-23 305.8 305.8 305.8