condition mean min max ZT0-3 7.18445 6.9181550000000005 7.4507449999999995 ZT4-7 13.99305 13.99305 13.99305 ZT8-11 22.43325 22.43325 22.43325 ZT12-15 0 0 0 ZT16-19 15.5574 15.5574 15.5574 ZT20-23 11.17785 11.17785 11.17785