condition mean min max ZT0-3 14.232355 14.232355 14.232355 ZT4-7 16.719976000000003 16.719976000000003 16.719976000000003 ZT8-11 16.158268 16.158268 16.158268 ZT12-15 17.217941 17.217941 17.217941 ZT16-19 18.068188499999998 18.068188499999998 18.068188499999998 ZT20-23 19.9496695 19.9496695 19.9496695