condition mean min max ZT0-3 6.431405 6.431405 6.431405 ZT4-7 4.7122 4.7122 4.7122 ZT8-11 5.646775 5.646775 5.646775 ZT12-15 5.68796 5.68796 5.68796 ZT16-19 8.09148 8.09148 8.09148 ZT20-23 6.260265 6.260265 6.260265