Here you can compare the ZEN inflation to other coins:

https://docs.google.com/spreadsheets/d/1-weHt0PiIZWyXs1Uzp7QIUKk9TX7aa15RtFc8JJpn7g/edit#gid=237137882

ZEN inflation calculated around June is 29,23% on an annualised basis.

Please note that I did not check the numbers. Please also note that the halving is not factored in.

The original article quoting the above table is here and is about PIVX Economics: https://pivx.freshdesk.com/support/solutions/articles/30000029620-pivx-economics