Available Bytes Counter Definition is Incorrect in Perfmon

Available Bytes displays the size of the virtual memory currently on the
Zeroed, Free, and Standby lists. Zeroed and Free memory is ready for
use, with Zeroed memory cleared to zeros. Standby memory is memory
removed from a process's Working Set but still available. Notice that
this is an instantaneous count, not an average over the time interval.

Available Bytes is the amount of physical memory available to processes
running on the computer, in bytes. It is calculated by summing space on
the Zeroed, Free, and Standby memory lists. Free memory is ready for
use; Zeroed memory is pages of memory filled with zeros to prevent later
processes from seeing data used by a previous process. Standby memory is
memory removed from a process's working set (its physical memory) on
route to disk, but is still available to be recalled.