condition mean min max ZT0-3 2.3495375000000003 2.19807 2.501005 ZT4-7 2.77803 2.77803 2.77803 ZT8-11 2.6051 2.6051 2.6051 ZT12-15 0 0 0 ZT16-19 3.199745 3.199745 3.199745 ZT20-23 2.7560700000000002 2.7560700000000002 2.7560700000000002