condition mean min max ZT0-3 2.618665 1.99716 3.24017 ZT4-7 1.014511 1.014511 1.014511 ZT8-11 0.4062935 0.4062935 0.4062935 ZT12-15 0 0 0 ZT16-19 3.2891 3.2891 3.2891 ZT20-23 3.00366 3.00366 3.00366