condition mean min max ZT0-3 1.3313925000000002 1.2989700000000002 1.363815 ZT4-7 2.38326 2.38326 2.38326 ZT8-11 3.5141850000000003 3.5141850000000003 3.5141850000000003 ZT12-15 0 0 0 ZT16-19 3.7053900000000004 3.7053900000000004 3.7053900000000004 ZT20-23 2.568165 2.568165 2.568165