Rolling Update Batch Size Question

The example in the documentation is as follows:

`

- name: test play
  hosts: webservers
  serial:
  - 1
  - 5
  - "20%"

`

With regards to the the last item (20%) - will this only perform actions on the remaining 20% or will it repeatedly do 20% of hosts until the end ? If I changed 20% to 100%, would it then action the tasks on all remaining hosts (excluding the 6 that have already completed) ?

Thanks in advance.

The documentation also cover that
"The serial keyword can also be specified as a percentage, which will be applied to the total number of hosts in a play"