|Variable                     |   N|       Mean|      SD|    Min| Median|      Max|
|:----------------------------|---:|----------:|-------:|------:|------:|--------:|
|Standardized mean difference | 291|     -0.126|   0.127| -0.702| -0.124|    0.333|
|Standard error               | 291|      0.019|   0.026|      0|  0.009|     0.14|
|Sample size (n)              | 291| 446416.605|      NA|    275|  50000| 10884922|
|z-statistic                  | 291|     37.785| 133.688|      0| 10.992|     1775|
|Composition                  |  NA|         NA|      NA|     NA|     NA|       NA|
|Primary education            | 196|      67.4%|      NA|     NA|     NA|       NA|
|Secondary education          |  95|      32.6%|      NA|     NA|     NA|       NA|
|Mathematics                  | 128|        44%|      NA|     NA|     NA|       NA|
|Reading                      | 161|      55.3%|      NA|     NA|     NA|       NA|
|Mixed                        |   2|       0.7%|      NA|     NA|     NA|       NA|
