The Dutch Aerospace Center (NLR) office in Amsterdam detects numerous GNSS jammers passing by every day.
On the 31st of January the Dutch Institute for Navigation hosted a workshop on GNSS interference. NLR provided an excellent overview presentation describing the many ways in which GNSS signals are disrupted. The below graph was at the end of the presentation in a backup slide. To our estimating eye, it looks like the daily average is somewhere around 30 events.