The 5th sprint took place from 04/12/2017 to 21/12/2017 (nearly 3 weeks).
The sprint review and retrospective didn't take place on Friday 21st December as planned because the team decided so based on:
The final picture of the sprint backlog is:
As we can see,
And the burn-down charts:
From the Scrum Master point of view, I can say that: