condition mean min max ZT0-3 6.4613662215000005 6.210577284 6.712155159 ZT4-7 5.824112705 5.085279137500001 6.5629462725 ZT8-11 7.551017557250001 7.193091387000001 7.9089437275000005 ZT12-15 6.32035878425 6.0280081275 6.612709441 ZT16-19 7.257329357 6.3021918495 8.2124668645 ZT20-23 16.3062555925 13.100752555 19.511758630000003