condition mean min max ZT0-3 3.491415 3.491415 3.491415 ZT4-7 2.3416050000000004 2.3416050000000004 2.3416050000000004 ZT8-11 2.594105 2.594105 2.594105 ZT12-15 3.631745 3.631745 3.631745 ZT16-19 4.65396 4.65396 4.65396 ZT20-23 3.081655 3.081655 3.081655