condition mean min max ZT0-3 250.790351 250.790351 250.790351 ZT4-7 248.0400175 248.0400175 248.0400175 ZT8-11 255.7122025 255.7122025 255.7122025 ZT12-15 257.5865495 257.5865495 257.5865495 ZT16-19 257.3590035 257.3590035 257.3590035 ZT20-23 260.8013385 260.8013385 260.8013385