In the Herald today, based on Scottish Government figures released ‘after being pressed by the Herald’ (Don’t snigger):

It also means six per cent of all of Scotland’s confirmed Covid cases first became ill in hospital after being admitted for a different reason.

A quick search finds these NHS England figures in the Guardian on 17th May:

Up to 20% of hospital patients with Covid-19 caught it at hospital. Up to a fifth of patients with Covid-19 in several hospitals contracted the disease over the course of the pandemic while already being treated there for another illness, NHS bosses have told senior doctors and nurses.

https://www.theguardian.com/world/2020/may/17/hospital-patients-england-coronavirus-covid-19

Outsourced cleaning?

Do the arithmetic?