| Kind | Value | annotation | ||
| enumeration | 1_very soft | |||
| enumeration | 2_very soft to soft | |||
| enumeration | 3_soft | |||
| enumeration | 4_soft to medium | |||
| enumeration | 5_medium | |||
| enumeration | 6_medium to firm | |||
| enumeration | 7_firm | |||
| enumeration | 8_firm to very firm | |||
| enumeration | 9_very firm |