condition mean min max ZT0-3 3.76143 3.76143 3.76143 ZT4-7 7.3782049999999995 7.3782049999999995 7.3782049999999995 ZT8-11 3.9016150000000005 3.9016150000000005 3.9016150000000005 ZT12-15 2.472125 2.472125 2.472125 ZT16-19 2.552495 2.552495 2.552495 ZT20-23 2.45572 2.45572 2.45572