condition mean min max ZT0-3 15.624342 15.624342 15.624342 ZT4-7 15.190173000000001 15.190173000000001 15.190173000000001 ZT8-11 14.7662595 14.7662595 14.7662595 ZT12-15 14.4557585 14.4557585 14.4557585 ZT16-19 14.6267905 14.6267905 14.6267905 ZT20-23 14.016078 14.016078 14.016078