condition mean min max ZT0-3 336.116957 336.116957 336.116957 ZT4-7 266.0821505 266.0821505 266.0821505 ZT8-11 231.393649 231.393649 231.393649 ZT12-15 281.8168635 281.8168635 281.8168635 ZT16-19 404.53978 404.53978 404.53978 ZT20-23 399.9748695 399.9748695 399.9748695