condition mean min max ZT0-3 1.3439843333333332 0.926098 2.00568 ZT4-7 1.1805335 1.1805335 1.1805335 ZT8-11 5.239865 5.239865 5.239865 ZT12-15 9.546515 8.26819 10.82484 ZT16-19 7.948180000000001 7.948180000000001 7.948180000000001 ZT20-23 3.9885450000000002 3.9885450000000002 3.9885450000000002