condition mean min max ZT0-3 15.511524999999999 14.9416 16.08145 ZT4-7 8.2594 8.2594 8.2594 ZT8-11 7.125335 7.125335 7.125335 ZT12-15 0 0 0 ZT16-19 10.12198 10.12198 10.12198 ZT20-23 11.92465 11.92465 11.92465