condition mean min max ZT0-3 40.509507 40.509507 40.509507 ZT4-7 27.875329 27.875329 27.875329 ZT8-11 12.886335500000001 12.886335500000001 12.886335500000001 ZT12-15 19.15905 19.15905 19.15905 ZT16-19 11.537062 11.537062 11.537062 ZT20-23 20.1994415 20.1994415 20.1994415