为什么IIS / ASP.Net / MVC3将max-age设置为7200？

I have an ASP.Net MVC 3 web application that I am using to deliver files (in this specific test, pdf files). The files won't ever change (if the file changes, a new URL is generated). So I would like to set the max-age (for Cache-Control), to 31536000 (1 year).I have an ASP.Net MVC 3 web application that I