condition mean min max ZT0-3 6.670495 4.792975 8.548015 ZT4-7 4.698435 4.698435 4.698435 ZT8-11 6.53293 6.53293 6.53293 ZT12-15 0 0 0 ZT16-19 6.507835 6.507835 6.507835 ZT20-23 7.892245000000001 7.892245000000001 7.892245000000001