condition mean min max ZT0-3 9.782608333333334 9.285260000000001 10.279125 ZT4-7 8.568154999999999 8.568154999999999 8.568154999999999 ZT8-11 9.729305 9.729305 9.729305 ZT12-15 16.929125 16.6276 17.23065 ZT16-19 13.48385 13.48385 13.48385 ZT20-23 14.48715 14.48715 14.48715