condition mean min max ZT0-3 307.307726 307.307726 307.307726 ZT4-7 193.113972 193.113972 193.113972 ZT8-11 192.88375100000002 192.88375100000002 192.88375100000002 ZT12-15 227.0807345 227.0807345 227.0807345 ZT16-19 303.79322149999996 303.79322149999996 303.79322149999996 ZT20-23 282.586478 282.586478 282.586478