condition mean min max ZT0-3 5.2556475 5.138165 5.37313 ZT4-7 1.421495 1.421495 1.421495 ZT8-11 2.0007200000000003 2.0007200000000003 2.0007200000000003 ZT12-15 0 0 0 ZT16-19 8.970234999999999 8.970234999999999 8.970234999999999 ZT20-23 3.93947 3.93947 3.93947