condition mean min max ZT0-3 12.868473333333332 9.70047 14.7041 ZT4-7 11.5448 11.5448 11.5448 ZT8-11 5.905575000000001 5.905575000000001 5.905575000000001 ZT12-15 6.109495 5.901255 6.317735 ZT16-19 7.931665000000001 7.931665000000001 7.931665000000001 ZT20-23 10.39255 10.39255 10.39255