condition mean min max ZT0-3 9.815782 9.815782 9.815782 ZT4-7 9.765189 9.765189 9.765189 ZT8-11 10.64193 10.64193 10.64193 ZT12-15 18.878352500000002 18.878352500000002 18.878352500000002 ZT16-19 9.619142 9.619142 9.619142 ZT20-23 17.968901 17.968901 17.968901