condition mean min max ZT0-3 6.08437 6.08437 6.08437 ZT4-7 4.414385 4.414385 4.414385 ZT8-11 5.26359 5.26359 5.26359 ZT12-15 5.657705 5.657705 5.657705 ZT16-19 7.491385 7.491385 7.491385 ZT20-23 5.9186250000000005 5.9186250000000005 5.9186250000000005