condition mean min max ZT0-3 2.73233 2.4294700000000002 2.95776 ZT4-7 2.6647499999999997 2.6647499999999997 2.6647499999999997 ZT8-11 1.68242 1.68242 1.68242 ZT12-15 1.7571025 1.398075 2.11613 ZT16-19 2.31687 2.31687 2.31687 ZT20-23 2.43703 2.43703 2.43703