I found this snip in dpkg.log
2016-05-06 20:20:59 status config-files linux-image-extra-4.4.0-18-generic:amd64 4.4.0-18.34
2016-05-06 20:21:00 status config-files linux-image-extra-4.4.0-18-generic:amd64 4.4.0-18.34
2016-05-16 21:01:00 upgrade linux-image-4.4.0-22-generic:amd64 4.4.0-22.39 4.4.0-22.40
2016-05-16 21:01:00 status half-configured linux-image-4.4.0-22-generic:amd64 4.4.0-22.39
2016-05-16 21:01:00 status unpacked linux-image-4.4.0-22-generic:amd64 4.4.0-22.39
2016-05-16 21:01:00 status half-installed linux-image-4.4.0-22-generic:amd64 4.4.0-22.39
2016-05-16 21:01:04 status half-installed linux-image-4.4.0-22-generic:amd64 4.4.0-22.39
2016-05-16 21:01:04 status unpacked linux-image-4.4.0-22-generic:amd64 4.4.0-22.40
2016-05-16 21:01:04 status unpacked linux-image-4.4.0-22-generic:amd64 4.4.0-22.40
2016-05-16 21:01:05 upgrade linux-image-extra-4.4.0-22-generic:amd64 4.4.0-22.39 4.4.0-22.40
2016-05-16 21:01:05 status half-configured linux-image-extra-4.4.0-22-generic:amd64 4.4.0-22.39
2016-05-16 21:01:05 status unpacked linux-image-extra-4.4.0-22-generic:amd64 4.4.0-22.39
there were 1013 occurrences of half-configured and 866 of half installed.