Diagram weekly sorted by number not by time

[AeOeAa]

Describe the bug When seeing diagram of measurements by week, the x-axis show week numbers but not in the correct order.

To Reproduce Steps to reproduce the behavior:

1. Go to Diagram
2. Click on icon with 3 horizontal lines
3. Select "weekly"
4. Scroll measurements horizontally
5. Notice order of "Wxx"

Reproduced with 2.5.2 64

Expected behavior Week numbers in chronological order.