reached five hundred thousand readers
Does "which reached five hundred thousand readers" mean "that specific issue exceptionally reached five hundred thousand readers" or "that issue like the other issues had five hundred thousand readers"? Because, according to Wikipedia, this newspaper usually has between 3.5 and 4.5 hundred thousand readers.

Context:
In Lustmord (1993–1994), a mixed-media installation, she comments on the rape of women in wartime from three different perspectives (the Observer, the Perpetrator and the Victim). One element, the photographic images of the text written on human skin, appeared in the magazine of the German newspaper Suddeutsche Zeitung. The ink used on the cover of this magazine, which reached five hundred thousand readers, contained women’s blood.

Question

reached five hundred thousand readers
Does "which reached five hundred thousand readers" mean "that specific issue exceptionally reached  five hundred thousand readers" or "that issue like the other issues had five hundred thousand readers"? Because, according to Wikipedia, this newspaper usually has between 3.5 and 4.5 hundred thousand readers.

Context:
In Lustmord (1993–1994), a mixed-media installation, she comments on the rape of women in wartime from three different perspectives (the Observer, the Perpetrator and the Victim). One element, the photographic images of the text written on human skin, appeared in the magazine of the German newspaper Suddeutsche Zeitung. The ink used on the cover of this magazine, which reached five hundred thousand readers, contained women’s blood.

Answer

It just means the issue reached five hundred thousand readers.

Answer

The word 'reach' has two different possible uses here:

1,000,000 refugees reached safety in 2012.

The number of refugees reached 1,000,000 in 2012.

In the first statement, 'reach' refers to each refugee, they each achieve safety. There is no information here about whether the number was rising or falling. In the the second statement 'reach' refers to the number, and implies that there were more in 2012 than before.

Similar logic is used here; each of 500,000 copies of the magazine was read. As with the first statement above, 'reach' does not refer to the number.

Answer

The main clue is that they talk about the ink on this issue.