condition mean min max ZT0-3 20.428449540499997 18.764209050999998 22.09269003 ZT4-7 4.18764432375 2.667791763 5.707496884499999 ZT8-11 10.039512648 5.858765064 14.220260232000001 ZT12-15 23.1023800975 18.699588704999996 27.505171490000002 ZT16-19 20.9147838325 20.78698936 21.042578305 ZT20-23 22.035438659999997 20.853216905 23.217660414999997