condition mean min max ZT0-3 1.3644475 0.976259 1.752636 ZT4-7 1.6721460000000001 1.6721460000000001 1.6721460000000001 ZT8-11 1.953045 1.953045 1.953045 ZT12-15 0 0 0 ZT16-19 4.53123 4.53123 4.53123 ZT20-23 3.7516350000000003 3.7516350000000003 3.7516350000000003