condition mean min max ZT0-3 8.675507499999998 8.25371 9.097304999999999 ZT4-7 6.56789 6.56789 6.56789 ZT8-11 7.74295 7.74295 7.74295 ZT12-15 0 0 0 ZT16-19 9.539175 9.539175 9.539175 ZT20-23 7.30206 7.30206 7.30206