condition mean min max ZT0-3 5.1581 5.1581 5.1581 ZT4-7 4.420295 4.420295 4.420295 ZT8-11 4.23878 4.23878 4.23878 ZT12-15 4.71382 4.71382 4.71382 ZT16-19 8.00036 8.00036 8.00036 ZT20-23 6.22883 6.22883 6.22883