German to English Science Mathematics & Statistics Numerical notation

This is a use of an apostrophe in a German text that I haven't seen before. Example: 78'015. Is the apostrophe equivalent to a decimal point, to a comma (as often used in English to separate groups of 3 digits in a large number), to a space, or to something specific to the technical context? Decimal point seems unlikely, as the German equivalent would be a comma, not an apostrophe. Here the data are apparently bacteria counts per ml, but I do not know the special field well enough to make a confident guess at the meaning.