condition mean min max ZT0-3 21.428975 21.311500000000002 21.54645 ZT4-7 30.247 30.247 30.247 ZT8-11 42.047 42.047 42.047 ZT12-15 0 0 0 ZT16-19 17.0393 17.0393 17.0393 ZT20-23 7.82558 7.82558 7.82558