The counts should be related to the digits by a logarithmic/exponential relationship.
A 1 digit meter can measure anything from 0 to 9, or 10 ^ 1 counts.
A 2 digit meter can measure anything from 0 to 99, or 10 ^ 2 counts.
A 3 digit meter goes to 10 ^ 3 counts.
A 4 digit meter goes to 10 ^ 4 counts.
You can see the logarithmic trend. We have the following equations, which should, in theory, be extendable to fractional digits.
counts = 10 ^ digits
digits = log10(counts)
A 3 1/2 digit meter, therefore, ought to have about 10 ^ 3.5 counts. That's pretty close to 3000 counts.
A 2000 count meter ought to be called a 3.3 digit meter or maybe 3 1/3 digits.
5 3/4 digits should be 56243 counts, which would be rounded to 50000 or 60000.
I realize that I'm approaching this from an engineering mindset, while many in the marketing department people don't understand logarithms and/or try to play fast and loose with the numbers to push them to whatever they can get away with. So don't take these too literally. In practice, you can't trust the fractional number of digits claimed; you've got to ask for the counts.