condition mean min max ZT0-3 11.043624999999999 10.91725 11.17 ZT4-7 12.15895 12.15895 12.15895 ZT8-11 12.12865 12.12865 12.12865 ZT12-15 0 0 0 ZT16-19 13.039000000000001 13.039000000000001 13.039000000000001 ZT20-23 12.9428 12.9428 12.9428