condition mean min max ZT0-3 7.8965575 7.32029 8.472825 ZT4-7 5.710485 5.710485 5.710485 ZT8-11 6.270165 6.270165 6.270165 ZT12-15 0 0 0 ZT16-19 6.664580000000001 6.664580000000001 6.664580000000001 ZT20-23 5.555854999999999 5.555854999999999 5.555854999999999