Many users want to clear data usage statistics on their Android. Unfortunately, there is no option in settings. You can change Data Usage Cycle, but this isn’t what many users want. After some investigation, I found a solution.

If your Android device is rooted, you can reset data usage statistics with removing some files.

Simply delete (or better move) all files from /data/system/netstats folder and restart a device.
I suggest ES File Explorer for this procedure – a super app for file management on Android. Of course, you can use any other (root consciousness) file manager or even a terminal window. 

In terminal window write:
$ su
# rm /data/system/netstats/*

And restart the device. It works for me, but I can’t guarantee that it will works on your device. Be careful – if your device is rooted, you can change/delete some important files!
Please – leave comments if this still works.
Check also some more interesting Android articles on blog or read latest Best battery saving tips.