condition mean min max ZT0-3 4.8023975 4.30914 5.295655 ZT4-7 6.063465 6.063465 6.063465 ZT8-11 8.53044 8.53044 8.53044 ZT12-15 0 0 0 ZT16-19 7.805665 7.805665 7.805665 ZT20-23 6.596285 6.596285 6.596285