Hi francoisnoah819.
The current mean GMAT score, which is based on scores from the past three years, is 575.51.
However, the mean score and the 50th percentile score are not the same. The 50th percentile score is basically a median score; the definition of the 50th percentile score is that it's higher than 50 percent of test scores for the relevant period.
So, currently, the 50th percentile score is 600, as your score report says.
For more on mean and percentile GMAT scores, see this post.
https://www.mba.com/exams/gmat-exam/sco ... your-score