condition mean min max ZT0-3 63.949999999999996 63.949999999999996 63.949999999999996 ZT4-7 7.3 7.3 7.3 ZT8-11 12.200000000000001 12.200000000000001 12.200000000000001 ZT12-15 33.8 33.8 33.8 ZT16-19 38.050000000000004 38.050000000000004 38.050000000000004 ZT20-23 51.6 51.6 51.6