condition mean min max ZT0-3 9.236491 9.236491 9.236491 ZT4-7 10.187873 10.187873 10.187873 ZT8-11 8.993810499999999 8.993810499999999 8.993810499999999 ZT12-15 10.606562499999999 10.606562499999999 10.606562499999999 ZT16-19 9.796948 9.796948 9.796948 ZT20-23 13.719366999999998 13.719366999999998 13.719366999999998