condition mean min max ZT0-3 14.164575 13.9269 14.402249999999999 ZT4-7 16.42515 16.42515 16.42515 ZT8-11 20.933100000000003 20.933100000000003 20.933100000000003 ZT12-15 0 0 0 ZT16-19 23.6356 23.6356 23.6356 ZT20-23 19.8293 19.8293 19.8293