condition mean min max ZT0-3 5.662599999999999 5.45557 5.86963 ZT4-7 4.334905 4.334905 4.334905 ZT8-11 12.657350000000001 12.657350000000001 12.657350000000001 ZT12-15 0 0 0 ZT16-19 10.09463 10.09463 10.09463 ZT20-23 8.351865 8.351865 8.351865