condition mean min max ZT0-3 5.608655 3.584555 9.519105 ZT4-7 9.570335 9.570335 9.570335 ZT8-11 3.6301 3.6301 3.6301 ZT12-15 3.0555725000000002 2.64863 3.4625150000000002 ZT16-19 2.09353 2.09353 2.09353 ZT20-23 3.409615 3.409615 3.409615