condition mean min max ZT0-3 3.065065587 2.840335683 3.2897954909999996 ZT4-7 2.08029340575 1.343185368 2.8174014435 ZT8-11 2.2258485915 1.9039721104999998 2.5477250725 ZT12-15 1.96587457125 1.7241974354999998 2.2075517070000004 ZT16-19 1.863453732 1.5554782280000001 2.171429236 ZT20-23 5.2015560370000005 4.6457230455000005 5.7573890285000004