319-202-5899 calling @ ramdom times, leaving no massage and when answered is nothing but dead air. when calling the # you get only voice mail no name or company ID

I got the same at 3 in the afternoon. who this this and why do they call me like this?

gotten calls at various times and days from the same number 202-5899 they never leave a message, when you answer they dont say anything and just hang up.  When you call it back they answer and hang up.