condition mean min max ZT0-3 7.592630000000001 6.665825 8.519435000000001 ZT4-7 4.416425 4.416425 4.416425 ZT8-11 5.364555 5.364555 5.364555 ZT12-15 0 0 0 ZT16-19 7.014390000000001 7.014390000000001 7.014390000000001 ZT20-23 6.851955 6.851955 6.851955