condition mean min max ZT0-3 191.180706 191.180706 191.180706 ZT4-7 258.02686 258.02686 258.02686 ZT8-11 303.599238 303.599238 303.599238 ZT12-15 283.2914445 283.2914445 283.2914445 ZT16-19 239.9205495 239.9205495 239.9205495 ZT20-23 223.888652 223.888652 223.888652