condition mean min max ZT0-3 8.919184999999999 8.11125 9.72712 ZT4-7 6.32291 6.32291 6.32291 ZT8-11 7.933275 7.933275 7.933275 ZT12-15 0 0 0 ZT16-19 8.710145 8.710145 8.710145 ZT20-23 7.670864999999999 7.670864999999999 7.670864999999999