| 2005 | 2011 | 2013 | 2015 | |
|---|---|---|---|---|
| Hamburg | 1.76 | 2.18 | 2.26 | 2.23 |
| Berlin | 3.48 | 3.32 | 3.55 | 3.54 |
| Brandenburg | 1.17 | 1.64 | 1.54 | 1.64 |
| Bayern | 2.89 | 2.99 | 3.13 | 3.15 |
| Bremen | 2.14 | 2.71 | 2.70 | 2.77 |
| Nordrhein-Westfalen | 1.72 | 1.96 | 1.92 | 1.95 |
| Rheinland-Pfalz | 1.66 | 1.99 | 2.12 | 2.34 |
| Saarland | 1.01 | 1.47 | 1.44 | 1.54 |
| Niedersachsen | 2.23 | 2.74 | 2.85 | 3.44 |
| Sachsen-Anhalt | 1.21 | 1.47 | 1.41 | 1.39 |
| Schleswig-Holstein | 1.14 | 1.40 | 1.47 | 1.47 |
| Baden-Württemberg | 4.07 | 4.79 | 4.77 | 4.92 |
| Sachsen | 2.37 | 2.79 | 2.75 | 2.71 |
| Thüringen | 1.87 | 2.11 | 2.15 | 2.00 |
| Hessen | 2.46 | 2.89 | 2.81 | 2.81 |
| Mecklenburg-Vorpommern | 1.45 | 2.04 | 1.80 | 1.86 |