condition mean min max ZT0-3 7.28423 6.202565 8.365895 ZT4-7 5.347770000000001 5.347770000000001 5.347770000000001 ZT8-11 6.021015 6.021015 6.021015 ZT12-15 0 0 0 ZT16-19 7.668089999999999 7.668089999999999 7.668089999999999 ZT20-23 7.929025 7.929025 7.929025