condition mean min max ZT0-3 22.069603333333333 6.769209999999999 33.6376 ZT4-7 8.173015 8.173015 8.173015 ZT8-11 6.068230000000001 6.068230000000001 6.068230000000001 ZT12-15 9.27354 8.682044999999999 9.865035 ZT16-19 5.61969 5.61969 5.61969 ZT20-23 17.90155 17.90155 17.90155