condition mean min max ZT0-3 8.529595 6.115125000000001 9.752235 ZT4-7 5.5458 5.5458 5.5458 ZT8-11 4.52255 4.52255 4.52255 ZT12-15 9.6572225 9.371929999999999 9.942515 ZT16-19 7.3535900000000005 7.3535900000000005 7.3535900000000005 ZT20-23 10.403035 10.403035 10.403035