https://cn.vogon.today/%e9%ab%98%e9%a3%9b%e7%b6%93%e6%bf%9f%e5%ad%b8/%e7%b5%b1%e4%b8%80%e7%a8%85%e7%9a%84%e7%b4%af%e9%80%b2%e6%80%a7/
統一稅的累進性