2007 Exchange Activeync devices

Hello All,

I have a 2007 exchange server with rollup 9, I am trying to clean up all the devices that are cached to our exchange server after 1 year the below command shows me the devices statistics but how can I deleted/remove all devices with LastSyncAttempttime ? 

get-mailbox | get-activesyncdevicestatistics -mailbox {$_.alias}