Notation	Name	Description	Status
0	Small swarm less than 1 km2 or adults in ground, tens or hundreds of individuals visible simultaneously, duration of passage less than 1 hour ago		stable
1	Area covered by isolated bands < 10 m2		stable
2	Area covered by isolated bands 10 - 100 m2		stable
3	Area covered by isolated bands 100 - 1000 m2		stable
4	Area covered by isolated bands 1 000 - 10000 m2		stable
5	Area covered by isolated bands 1 - 10 ha		stable
6	Area covered by isolated bands > 10 ha		stable
7	Area covered by dispersed bands < 100 km2		stable
8	Area covered by dispersed bands 100 - 1000 km2		stable
9	Area covered by dispersed bands > 1000 km2		stable
10	Size of swarm and/or duration of passage not determined owing to darkness or similar phenomena		stable
15	Missing value		stable