condition mean min max ZT0-3 8.782575 8.782575 8.782575 ZT4-7 9.929304 9.929304 9.929304 ZT8-11 9.263730500000001 9.263730500000001 9.263730500000001 ZT12-15 9.1652105 9.1652105 9.1652105 ZT16-19 8.938499 8.938499 8.938499 ZT20-23 11.063271499999999 11.063271499999999 11.063271499999999