condition mean min max ZT0-3 6.0344275 4.630275 7.43858 ZT4-7 6.55837 6.55837 6.55837 ZT8-11 0.463414 0.463414 0.463414 ZT12-15 0 0 0 ZT16-19 0.1947445 0.1947445 0.1947445 ZT20-23 6.80186 6.80186 6.80186