You are required to build a dashboard widget that visualizes demographic data. The widget will fetch 200 random birth years and display their distribution across decades in a histogram.

Core Requirements:

Data Fetching: Fetch 200 integers between 1950 and 2019 from the Random.org API.
Aggregation: Process the flat list of years into "decade buckets" (e.g., 1950–1959, 1960–1969).
Visualization:
- Plot a histogram where the X-axis represents the decades.
- The Y-axis represents the count of occurrences in that decade.
- The Y-axis must have clear labels or a scale.
Loading State: Show a loading indicator while the data is being fetched.

API Details:

URL: https://www.random.org/integers/?num=200&min=1950&max=2019&col=1&base=10&format=plain&rnd=new
Method: GET
Format: The API returns a plain text string with one number per line.