Debian LinuxパッケージCUPSの特定のバージョンをインストールするには？

特定のバージョンをインストールしようとしています。(2.2.1-8+deb9u2)~のコンピュータ支援システムカプセル化Debian:ストレッチスリム Linux。ただし、次のエラーが発生します。

$apt install -y cups=2.2.1-8+deb9u2
Reading package lists...
Building dependency tree...
Reading state information...
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 cups : Depends: libcups2 (= 2.2.1-8+deb9u2) but 1.7.5-11+deb8u4 is to be installed
        Depends: libstdc++6 (>= 5) but 4.9.2-10+deb8u1 is to be installed
        Depends: cups-core-drivers (>= 2.2.1-8+deb9u2) but 1.7.5-11+deb8u4 is to be installed
        Depends: cups-daemon (>= 2.2.1-8+deb9u2) but 1.7.5-11+deb8u4 is to be installed
        Depends: cups-common (>= 2.2.1-8+deb9u2) but 1.7.5-11+deb8u4 is to be installed
        Depends: cups-server-common (>= 2.2.1-8+deb9u2) but 1.7.5-11+deb8u4 is to be installed
        Depends: cups-client (>= 2.2.1-8+deb9u2) but 1.7.5-11+deb8u4 is to be installed
        Recommends: avahi-daemon but it is not going to be installed
        Recommends: colord but it is not going to be installed
        Recommends: printer-driver-gutenprint but it is not going to be installed
Unable to correct problems, you have held broken packages.
The command 'apt install -y cups=2.2.1-8+deb9u2' returned a non-zero code: 100
Build step 'Execute shell' marked build as failure
Finished: FAILURE

私はどこで間違っていますか？

インストール理由1.7.5-11+deb8u4インストールしますか？

ここで何か抜けましたか？

$ apt-cache policy cups
cups:
  Installed: 1.7.5-11+deb8u4
  Candidate: 1.7.5-11+deb8u4
  Version table:
     2.2.1-8+deb9u2 0
        -10 http://deb.debian.org/debian/ stretch/main amd64 Packages
     2.2.1-8+deb9u1~bpo8+1 0
        100 http://deb.debian.org/debian/ jessie-backports/main amd64 Packages
*** 1.7.5-11+deb8u4 0
        500 http://security.debian.org/debian-security/ jessie/updates/main amd64 Packages
        100 /var/lib/dpkg/status
     1.7.5-11+deb8u2 0
        500 http://deb.debian.org/debian/ jessie/main amd64 Packages

なぜインストールできないのですか？2.2.1-8deb9u2バージョンダーバン8？