Guilin airport shuttle bus

You previously wrote that the airport shuttle bus leaves "After every flight arrival, there will be an bus waiting at the exit of the arrival hall leaving for the downtown area."
and
"Hi, yes. You can take the airport shuttle bus to local CAAC, which is near the Railway Station. It runs from 06:00 to 21:00 every 30 min."
So when is the last shuttle bus leaving? My flight would be at 22.00.