Need help on which Nexus 7 Image to download

Basically as alot of Nexus 7 users have previously noticed lollipop 5.1.1 slows down the device greatly.I have a Nexus 7 2012 WI-FI and i need to find a suitable factory image to download.I want to downgrade my Nexus 7 from 5.1.1 to 4.4.4.However i cannot find a download on the Google page.If anyone knows how to downgrade from 5.1.1 (LMY47V) to 4.4.4 can you please send me instructions or a link to download a image or an alternative on how to do so! Thanks for the help in advance

Kyle: )