condition mean min max ZT0-3 0.0385341 0.0385341 0.0385341 ZT4-7 0.0448043 0.0448043 0.0448043 ZT8-11 0.0 0.0 0.0 ZT12-15 0.0 0.0 0.0 ZT16-19 0.03961735 0.03961735 0.03961735 ZT20-23 0.07793710000000001 0.07793710000000001 0.07793710000000001