| Kind | Value | annotation | ||
| enumeration | 1_very wide open | |||
| enumeration | 2_wide open | |||
| enumeration | 3_half open | |||
| enumeration | 4_slightly open | |||
| enumeration | 5_closed | |||
| enumeration | 6_slightly overlapped | |||
| enumeration | 7_half overlapped | |||
| enumeration | 8_strongly overlapped | |||
| enumeration | 9_very strongly overlapped |