Understanding Free/Busy property of Outlook.

This is not necessarily a C# question per se, but I posted this here in the hope that someone knows about this.
I am looking up Recipient.FreeBusy method in the Outlook library.


Here's my code.

C# Code:

using System;
using System.Linq;
using Microsoft.Office.Interop.Outlook; //make sure to add a reference to the COM library Microsoft.Office.Interop.Outlook
 
namespace OutLookFreeBusy
{
    class Program
    {
        static void Main(string[] args)
        {
            var outlook = new Application();
            var mapi =  outlook.GetNamespace("MAPI");
            var reci = mapi.CreateRecipient("[email protected]"); //Replace this string with a valid email address
            Console.WriteLine("String data:\n {0}", reci.FreeBusy(new DateTime(2013, 11, 27), 60 * 24, true));
        }
    }
}

Now when I run my code, I get a valid string, but my question is to do with interpreting the string. I was expecting 24 characters to be returned with the snippet of code I posted, but I get 28 characters back.

From the documentation, each character represents 1 hour of activity. This is the part that is confusing me.
The string I get looks like this

PHP Code:

---

3332232222222222222222222222 


---

I counted the characters from different email addresses. Each time I get different values, but the total count stays at 28.