| 13
| 6 quite poor
| 11 rather easy
| 13 extremely easy
|
| 14
| 6 quite poor
| 11 rather easy
| 14 incredibly easy
|
| 15
| 6 quite poor
| 11 rather easy
| 14 incredibly easy
|
| 16
| 6 quite poor
| 12 very easy
| 14 incredibly easy
|
| 17
| 6 quite poor
| 12 very easy
| 14 incredibly easy
|
| 18
| 6 quite poor
| 12 very easy
| 14 incredibly easy
|
| 19
| 6 quite poor
| 12 very easy
| 14 incredibly easy
|
| 20
| 6 quite poor
| 12 very easy
| 14 incredibly easy
|
| 21
| 6 quite poor
| 12 very easy
| 14 incredibly easy
|
| 22
| 6 quite poor
| 12 very easy
| 14 incredibly easy
|
| 23
| 6 quite poor
| 12 very easy
| 14 incredibly easy
|
|
|