condition mean min max ZT0-3 1.262926 1.262926 1.262926 ZT4-7 1.0204715 1.0204715 1.0204715 ZT8-11 0.9943280000000001 0.9943280000000001 0.9943280000000001 ZT12-15 0.9744550000000001 0.9744550000000001 0.9744550000000001 ZT16-19 1.1392280000000001 1.1392280000000001 1.1392280000000001 ZT20-23 0.6083363333333334 0.6083363333333334 0.6083363333333334