condition mean min max ZT0-3 421.962406 421.962406 421.962406 ZT4-7 444.3464275 444.3464275 444.3464275 ZT8-11 620.151126 620.151126 620.151126 ZT12-15 609.2787894999999 609.2787894999999 609.2787894999999 ZT16-19 907.5007905 907.5007905 907.5007905 ZT20-23 728.50712 728.50712 728.50712