condition mean min max ZT0-3 12.6271 12.6271 12.6271 ZT4-7 13.2179 13.2179 13.2179 ZT8-11 6.967485 6.967485 6.967485 ZT12-15 4.8787199999999995 4.8787199999999995 4.8787199999999995 ZT16-19 6.45613 6.45613 6.45613 ZT20-23 8.24257 8.24257 8.24257