condition mean min max ZT0-3 3.0667833333333334 0.0 9.20035 ZT4-7 12.416345 12.416345 12.416345 ZT8-11 4.21546 4.21546 4.21546 ZT12-15 1.0288075 0.0 2.057615 ZT16-19 2.04354 2.04354 2.04354 ZT20-23 2.22218 2.22218 2.22218