condition mean min max ZT0-3 11.624324999999999 11.4625 11.78615 ZT4-7 11.96655 11.96655 11.96655 ZT8-11 11.939499999999999 11.939499999999999 11.939499999999999 ZT12-15 0 0 0 ZT16-19 14.42465 14.42465 14.42465 ZT20-23 12.540849999999999 12.540849999999999 12.540849999999999