condition mean min max ZT0-3 6.410950000000001 6.410950000000001 6.410950000000001 ZT4-7 7.423080000000001 7.423080000000001 7.423080000000001 ZT8-11 4.524430000000001 4.524430000000001 4.524430000000001 ZT12-15 4.76957 4.76957 4.76957 ZT16-19 6.14102 6.14102 6.14102 ZT20-23 7.579383333333333 7.579383333333333 7.579383333333333