Update dataset fact sheet with data skew

README.md

@@ -11,7 +11,7 @@ GitGoodBench Lite is a subset of 120 samples for evaluating the performance of A
 The samples in the dataset are evenly split across the programming languages Python, Java and Kotlin and the sample types merge conflict resolution and file-commit gram.
 This dataset thus contains 20 samples per sample type and programming language.
 
-All data in this dataset are collected from open-source repositories on GitHub with permissive licenses 
+All data in this dataset are collected from 105 unique, open-source GitHub repositories with permissive licenses 
 that have >= 1000 stars, >= 5 branches, >= 10 contributors and are not a fork or archived. We collected the initial list of repositories using [SEART.](https://seart-ghs.si.usi.ch/)
 
 Evaluation is to be performed by exact-match (EM) of diffs for the merge conflict setting and by LLM-as-a-Judge for the file-commit gram setting. [For further details see our paper.]()
@@ -43,6 +43,8 @@ File-commit chain scenarios consist of two commits, the oldest and newest commit
 In total the chain consists of `times_seen_consecutively` commits. The intended use-cases of these scenarios are to evaluate the agent's capacity to create meaningful, cohesive commits or 
 improve the local tree via rebasing. Thus samples of this `sample_type` cover two scenario types.
 
+File-commit chains are at least 3 commits long, all commits only contain files in the specified programming_language and no commit is a merge commit.
+
 A `file_commit_chain` scenario looks as follows:
 ```
 {
@@ -83,6 +85,35 @@ The following table provides per-field details. Columns marked “Yes” under *
 # Dataset statistics
 We provide some statistics on the distribution of “difficulty” within the overall dataset and across different scenario types.
 
+## Dataset Skew
+
+We note that our dataset is skewed towards the top three repositories especially, however skew flattens quickly.
+
+### Distribution Statistics
+- Total number of repositories (count): 105
+- Average (mean) samples per repository: 1.14
+- Standard deviation (std): 0.67
+- Minimum (min): 1
+- 25th percentile (25%): 1
+- Median (50%): 1
+- 75th percentile (75%): 1
+- Maximum (max): 7
+
+### Top-10 Repositories by Sample Count
+
+| Repository                               | Percentage of Total Samples |
+|------------------------------------------|----------------------------:|
+| oss-review-toolkit/ort                   | 5.83%                       |
+| stripe/stripe-android                    | 2.50%                       |
+| element-hq/element-android               | 2.50%                       |
+| tlaplus/tlaplus                          | 1.67%                       |
+| apache/hive                              | 1.67%                       |
+| wikimedia/apps-android-wikipedia         | 1.67%                       |
+| chrisbanes/tivi                          | 1.67%                       |
+| liquibase/liquibase                      | 1.67%                       |
+| spring-projects/spring-data-mongodb      | 0.83%                       |
+| mpv-android/mpv-android                  | 0.83%                       |
+
 ## Overall Difficulty Distribution
 | Difficulty | Fraction  |
 |------------|----------|