condition mean min max ZT0-3 8.901485 8.901485 8.901485 ZT4-7 10.0458785 10.0458785 10.0458785 ZT8-11 8.746363 8.746363 8.746363 ZT12-15 8.6458815 8.6458815 8.6458815 ZT16-19 8.737673000000001 8.737673000000001 8.737673000000001 ZT20-23 10.024112500000001 10.024112500000001 10.024112500000001