condition mean min max ZT0-3 32.727975 31.31995 34.136 ZT4-7 17.762900000000002 17.762900000000002 17.762900000000002 ZT8-11 11.75845 11.75845 11.75845 ZT12-15 0 0 0 ZT16-19 22.868499999999997 22.868499999999997 22.868499999999997 ZT20-23 28.1371 28.1371 28.1371