Since there was no data presented, I got the data from this site and responded to it. The date and time data columns are converted to date format by pandas, and the year information is added as a new column based on that. Run countplot on that column.
movies_rating.head()
user_id rating rating_timestamp movie_title genres
movie_id
8 42514 5 2014-04-08 18:20:11 Edison Kinetoscopic Record of a Sneeze (1894) Documentary|Short
10 69964 10 2014-10-09 18:15:53 La sortie des usines Lumiティre (1895) Documentary|Short
12 68927 10 2015-08-10 23:16:19 The Arrival of a Train (1896) Documentary|Short
25 37289 8 2017-02-27 10:04:59 The Oxford and Cambridge University Boat Race ... NaN
91 5759 6 2013-11-23 18:59:55 Le manoir du diable (1896) Short|Horror
movies_rating['rating_timestamp'] = pd.to_datetime(movies_rating['rating_timestamp'])
movies_rating['year'] = movies_rating['rating_timestamp'].dt.year
sns.countplot(x='year', data=movies_rating,)
