Sites using public-key-pins-report-only:
3,275 proton.me
6,963 protonmail.ch
9,159 protonmail.com
24,112 ddos-guard.net
104,278 protonvpn.ch
231,262 hackthissite.org
322,159 pm.me
388,364 proton.ch
406,042 peterjin.org
432,290 intellicureehr.com
807,208 twfeg.org