condition mean min max ZT0-3 2.75329 2.75329 2.75329 ZT4-7 1.96197 1.96197 1.96197 ZT8-11 1.30442 1.30442 1.30442 ZT12-15 1.70253 1.70253 1.70253 ZT16-19 5.18058 5.18058 5.18058 ZT20-23 3.378065 3.378065 3.378065