It appears as if the '9.5' component apt repo metadata is not generating properly. Although 9.5 packages are available under the 'main' component and package metadata exists for all other version specific components (9.3, 9.4, 9.6, etc) the 9.5 component is missing package lists under all distributions (trusty-pgdg, wheezy-pgdg, xenial-pgdg, etc) for both i386 and amd64 architectures.
You can see the Packages files are empty, for example