Least amount of fork fluid? - 04 YZ250 w/ 48mm KYB

I am looking for the specification of the least amount of fork fluid in cubic centimeters that can be put in an 04 YZ250 KYB 48mm front fork tube and still have the fork function properly. I know fluid that can be measured by height but I was just wondering if anyone knows offhand the least amount of cubic centimeters of fluid. According to the RaceTech site the fork is officially know as a "KYB 48U Cylinder Valve" if that matters. Thanks for any info.