As of Windows 10.0.28000.1251
Numbers represent the number of keys defined for given shift state.
To obtain an additional shift state, some keyboards have extra physical keys (such as VK_KANA), and some map physical keys to uncommon virtual keys (e.g. VK_OEM_8 in Canadian Multilingual Standard is mapped to the right Ctrl key), so make sure to check key mappings for these.
Ordered by number of shift states and the total number of keys defined.