Mozilla Observatory scans Alexa Top 1M websites using security tools such as Content Security Policy (CSP), HSTS (HSTS), and Subresource Integrity (SRI) The use of these technologies has increased by approximately 50% since the release of the Mozilla Observatory a year ago. A 36% increase in the number of sites that support HTTPS might seem small, but the absolute numbers are quite large it represents over 119,000 websites. Over 27,000 of the largest sites in the world have improved from a failing in the last eight months alone.”]
Source: https://blog.mozilla.org/security/2017/06/28/analysis-alexa-top-1m-sites/