Explanation of symbols in database
| Symbol | Explanation |
|
- |
Magnitude zero |
|
0 |
Less than half of the unit employed |
|
... |
Data not available or too uncertain for presentation |
|
X |
Figure not applicable because column heading and stub line make entry impossible, absurd or meaningless |
|
. |
Data not released for confidentiality reasons |
|
If data are absolute numbers |
|
|
0 |
Magnitude zero |