condition mean min max ZT0-3 1.93167247275 1.4405171540000001 2.4228277915 ZT4-7 3.44264975575 2.8341306665 4.051168845 ZT8-11 6.77347275225 5.268139247500001 8.278806257 ZT12-15 6.91494237825 6.582251629 7.2476331275 ZT16-19 4.45111020775 4.190055409999999 4.7121650055 ZT20-23 5.7908394575 5.541274504 6.040404410999999