For anyone curious about the rate, these articles https://www.usatoday.com/story/news/world/2017/04/27/acid-at... https://www.vice.com/en_au/article/z4dy43/why-acid-attacks-h... http://www.dailymail.co.uk/news/article-4462016/Two-acid-att... suggest that (on average) there is more than one attack per day in London alone.