condition mean min max ZT0-3 13.83258872 11.74746288 15.91771456 ZT4-7 17.574128125 14.174984760000001 20.973271490000002 ZT8-11 22.3839018475 20.277489995 24.490313699999998 ZT12-15 26.1019006975 25.989465005 26.21433639 ZT16-19 25.5220544575 24.502782595 26.541326320000003 ZT20-23 21.27183956 20.532672865000002 22.011006254999998