condition mean min max ZT0-3 6.17121 6.131375 6.211045 ZT4-7 5.18765 5.18765 5.18765 ZT8-11 6.855 6.855 6.855 ZT12-15 0 0 0 ZT16-19 8.039674999999999 8.039674999999999 8.039674999999999 ZT20-23 7.1557949999999995 7.1557949999999995 7.1557949999999995