condition mean min max ZT0-3 2.613271666666667 1.113825 5.507885 ZT4-7 2.16593 2.16593 2.16593 ZT8-11 0.0 0.0 0.0 ZT12-15 4.038740000000001 2.331435 5.7460450000000005 ZT16-19 3.128395 3.128395 3.128395 ZT20-23 3.6175300000000004 3.6175300000000004 3.6175300000000004