condition mean min max ZT0-3 11.182485 9.09667 13.2683 ZT4-7 21.83365 21.83365 21.83365 ZT8-11 19.2367 19.2367 19.2367 ZT12-15 0 0 0 ZT16-19 16.89065 16.89065 16.89065 ZT20-23 20.509900000000002 20.509900000000002 20.509900000000002