"Religions: Roman Catholic 23.6%, Protestant 14.9% (includes Dutch Reformed 6.4%, Protestant Church of The Netherlands 5.6%, Calvinist 2.9%), Muslim 5.1%, other 5.6% (includes Hindu, Buddhist, Jewish), none 50.7% (2017 est.)"
https://www.indexmundi.com/netherlands/religions.html
But the 50.7 % “none” are the now secularized nominally Protestant which brings Protestant up to 65%.