condition mean min max ZT0-3 16.525227317499997 15.786633134999999 17.2638215 ZT4-7 2.0466265957500003 1.4591624795000002 2.634090712 ZT8-11 2.617442359 1.7197303860000002 3.515154332 ZT12-15 3.970306032 3.7787383905 4.1618736735 ZT16-19 3.813646162 3.0418541315 4.5854381925 ZT20-23 7.536464775500001 7.443002577500001 7.6299269735