condition mean min max ZT0-3 20.21066666666667 18.7928 21.568350000000002 ZT4-7 25.9386 25.9386 25.9386 ZT8-11 24.8249 24.8249 24.8249 ZT12-15 33.522999999999996 32.67255 34.37345 ZT16-19 24.820050000000002 24.820050000000002 24.820050000000002 ZT20-23 24.11185 24.11185 24.11185