condition mean min max ZT0-3 4.5579775 4.437875 4.6780800000000005 ZT4-7 2.9783 2.9783 2.9783 ZT8-11 6.148440000000001 6.148440000000001 6.148440000000001 ZT12-15 0 0 0 ZT16-19 6.231075000000001 6.231075000000001 6.231075000000001 ZT20-23 7.27849 7.27849 7.27849