condition mean min max ZT0-3 3.011475 0.0 6.02295 ZT4-7 0.0 0.0 0.0 ZT8-11 6.12005 6.12005 6.12005 ZT12-15 0 0 0 ZT16-19 11.83285 11.83285 11.83285 ZT20-23 11.94235 11.94235 11.94235