condition mean min max ZT0-3 4.8181925 4.263395 5.37299 ZT4-7 6.23204 6.23204 6.23204 ZT8-11 4.983525 4.983525 4.983525 ZT12-15 0 0 0 ZT16-19 6.463665000000001 6.463665000000001 6.463665000000001 ZT20-23 5.983515000000001 5.983515000000001 5.983515000000001