Best possible method to compress .mdx files

[ipman_98]

Well, I have been trying compress .mdx files for a while now. I tried many compression methods. But still I haven't able to reach any considerable compression ratio (90% at most, so the file is only smaller than 10% of it's original size). I tried reflate, masked data compress... etc. I attached a sample part of my original file, splited using razor's file splitter. If anyone can help me with this, I really appreciate that.

I just want to make it smaller as possible. (Original file is 1.2GB)

sample file : https://drive.google.com/file/d/0BzH...ew?usp=sharing