Moodle size is too large

HI,

I'm using  Moodle version 3.6.1 on my PC,

I have some courses in that I have files like pdfs, videos, nearly all type of files. with all the data my moodle size is  87Gb.

Later I deleted some content up to 20Gb. and added new content 30GB with the old version(2.4)backup files.

So now my file size needs to be 117GB approximately. But it shows that my moodle file size is 167GB. in moodledata folder.

I tried to solve but not happened by running cron, deleting temp.  

How it can be possible ?? I don't understand, can somebody help me with this.