2H1 honours degree equivalent

Hi,

I´m interested in applying for the graduate medicine course. I´m not from Ireland or the UK, so I don´t have an 2H1 honours degree.

I asked UCD what the 2H1 honours degree equivalent is in my home country, and they said it should have an 8/10 average. On their site they also state "or
an equivalent qualification noting that a 2H1 corresponds to a 60% average, or a B minus or 3.08 GPA equivalent." http://www.ucd.ie/economics/graduateprogrammes/ma/#entry

I've looked for grades conversion tables, and this is what I found ( http://85.92.87.111/~artcypr/comparability.html )

Bachelors H2.1 (Eire)

=

• Bachelor degree (courses from 2002):
• Doctoraal
• Getuigschrift Hoger Beroepsonderwijs (HBO)

(The Netherlands)
Overall average of 7.0 to 7.9

How did UCD establish that a 2H1 corresponds with an 8.0? Shouldn't there be a universal conversion table?

Thanks.