condition mean min max ZT0-3 15.72785 15.72785 15.72785 ZT4-7 12.36695 12.36695 12.36695 ZT8-11 15.504349999999999 15.504349999999999 15.504349999999999 ZT12-15 20.089 20.089 20.089 ZT16-19 24.509700000000002 24.509700000000002 24.509700000000002 ZT20-23 23.14545 23.14545 23.14545