Finding All Available Versions of a Package in Ubuntu

How to find all available versions of a package in Ubuntu?

To list available versions of a package:

apt-cache showpkg <package-name>

For example, to check all versions of thunderbird:

$ sudo apt-cache showpkg thunderbird
Package: thunderbird
Versions: 
1:31.1.1+build1-0ubuntu0.14.04.1 (/var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_trusty-updates_main_binary-amd64_Packages) (/var/lib/apt/lists/security.ubuntu.com_ubuntu_dists_trusty-security_main_binary-amd64_Packages)
 Description Language: 
                 File: /var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_trusty_main_binary-amd64_Packages
                  MD5: 68ed1001b79d708ad48956a0c129114d
 Description Language: en
                 File: /var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_trusty_main_i18n_Translation-en
                  MD5: 68ed1001b79d708ad48956a0c129114d

1:31.0+build1-0ubuntu0.14.04.1 (/var/lib/dpkg/status)
 Description Language: 
                 File: /var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_trusty_main_binary-amd64_Packages
                  MD5: 68ed1001b79d708ad48956a0c129114d
 Description Language: en
                 File: /var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_trusty_main_i18n_Translation-en
                  MD5: 68ed1001b79d708ad48956a0c129114d

1:24.4.0+build1-0ubuntu1 (/var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_trusty_main_binary-amd64_Packages)
 Description Language: 
                 File: /var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_trusty_main_binary-amd64_Packages
                  MD5: 68ed1001b79d708ad48956a0c129114d
 Description Language: en
                 File: /var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_trusty_main_i18n_Translation-en
                  MD5: 68ed1001b79d708ad48956a0c129114d


Reverse Depends: 
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