Assess the level of the emotion joy in the tweet provided. Use the following categories: 0: no joy can be inferred, 1: low amount of joy can be inferred, 2: moderate amount of joy can be inferred, 3: high amount of joy can be inferred.
Tweet: Positive #psychology research shows salespeople who score in the top 10% for #optimism have 88% &gt; sales than those in top 10% for pessimism.
0: no joy can be inferred