condition mean min max ZT0-3 2.18003 0.0 3.82334 ZT4-7 0.0 0.0 0.0 ZT8-11 0.0 0.0 0.0 ZT12-15 0.0 0.0 0.0 ZT16-19 0.0 0.0 0.0 ZT20-23 8.68835 8.68835 8.68835