I've just began refilling my 564/564xl cartridges using an (SEE THIS) refill kit. I'm having difficulty determining the capacity of the cartridges. There's a lot of different information, on the internet, as to the capacity of these cartridges. I've read some really low numbers (2 ml) and some very high numbers (30 ml). The best that I can guess, is that 564 color cartridges hold 4.5 ml, 564 Black holds 8 mil, 564XL color holds 8 ml and 564XL Black holds 18 ml. Am I right or wrong?