Total coverage moves so slowly that it tells you nothing about the change in front of you, and the question a reviewer wants answered is whether the new code is tested.
$ vendor/bin/phpunit --coverage-clover=coverage.xml
$ git diff origin/master --unified=0 > changes.diff
$ php coverage-checker.php coverage.xml changes.diff 90
src/Billing/Vat.php 12 of 14 changed lines covered
src/Http/Controller.php 0 of 9 changed lines covered ← fails
Covered 12/23 (52%) of changed lines. Required: 90%.The tooling for this is a hundred lines of script parsing a clover file against a diff, and several small packages do it. It changes the conversation in review from a percentage nobody can act on to a list of lines. The threshold has to allow exceptions — a controller that is genuinely covered by a feature test rather than a unit test will show as uncovered under some configurations, and fighting that produces worse tests.