condition mean min max ZT0-3 21.078507 21.078507 21.078507 ZT4-7 23.830154 23.830154 23.830154 ZT8-11 24.774404 24.774404 24.774404 ZT12-15 22.917445 22.917445 22.917445 ZT16-19 27.5105435 27.5105435 27.5105435 ZT20-23 24.777426 24.777426 24.777426