condition mean min max ZT0-3 3.1714700000000002 2.749285 3.593655 ZT4-7 5.97331 5.97331 5.97331 ZT8-11 17.3876 17.3876 17.3876 ZT12-15 0 0 0 ZT16-19 11.549150000000001 11.549150000000001 11.549150000000001 ZT20-23 8.776955000000001 8.776955000000001 8.776955000000001