Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE event ( Event_ID int, Date text, Venue text, Name text, Event_Attendance int )
TABLE: CREATE TABLE news_report ( journalist_ID int, Event_ID int, Work_Type text )
TABLE: CREATE TABLE journalist ( journalist_ID int, Name text, Nationality text, Age text, Years_working int )

### Question ###
Visualize a bar chart for what are the nationalities and their average ages of journalists?, order total number in desc order please.

### Accurate SQL ###

SELECT Nationality, AVG(Age) FROM journalist GROUP BY Nationality ORDER BY AVG(Age) DESC