condition mean min max ZT0-3 17.141916666666667 13.19965 20.57285 ZT4-7 10.66815 10.66815 10.66815 ZT8-11 12.3002 12.3002 12.3002 ZT12-15 18.724275 16.21285 21.2357 ZT16-19 17.487499999999997 17.487499999999997 17.487499999999997 ZT20-23 18.7297 18.7297 18.7297