condition mean min max ZT0-3 7.414371666666667 4.929235 9.70374 ZT4-7 16.32625 16.32625 16.32625 ZT8-11 7.376995 7.376995 7.376995 ZT12-15 10.819890000000001 4.88763 16.75215 ZT16-19 11.561499999999999 11.561499999999999 11.561499999999999 ZT20-23 8.201575 8.201575 8.201575