Powershell custom sensor wrong value

Hi, i hope someone can help me... I'm working for now 2 weeks on a sensor, that shows me how old a backup is. The result from the PowerShell script is:

            <prtg>
            <result>
            <channel>Backup Job 1</channel>
            <value>21</value>
            </result>
            <result>
            <channel>Backup Job 2</channel>
            <value>248</value>
            </result>
            <result>
            <channel>Backup Job 3</channel>
            <value>18</value>
            </result>
            </prtg>

The scipt worked verry well, but when i create a custom XML sensor the values are wrong. In this case:

Backup Job 1 = 84
Backup Job 2 = 384	
Backup Job 3 = 194

The code is very simple: 

$BackupJob1 = "Backup Job 1"
$LastBackup1 = (Get-ChildItem 'backups:\Backup Job 1').LastWriteTime | Sort-Object LastWriteTime | Select-Object -Last 1
$BackupAge1 =  (Get-Date) - $LastBackupJonas | Select-Object -Property Days | Format-Wide | Out-String
$BackupAge1 = $BackupAge1.Trim()
$BackupAge1 = $BackupAge1.ToDecimal($null)

The integer that comes out of the Sript is right, but PRTG shows a different one... I don't know why and i can't see a scheme on it.

I hope some one can help me, I'm despairing.

Greetings from Germany

backup custom-sensor failure powershell prtg sensor value