condition mean min max ZT0-3 1.9718199570000001 1.204583804 2.73905611 ZT4-7 1.8052177114999999 1.6082156285 2.0022197944999998 ZT8-11 1.50760251725 1.3054537700000002 1.7097512645 ZT12-15 1.74515157475 1.6007086335 1.8895945159999998 ZT16-19 2.8612457685 2.703309367 3.0191821699999997 ZT20-23 4.973106308 4.2336082704999995 5.7126043455