What is this column in /proc/interrupts?

Can someone assist me in analyzing the data in this output from my /proc/interrupts file?

$ cat /proc/interrupts
           CPU0       CPU1
  0:         22          0  IR-IO-APIC   2-edge      timer
  1:          2          0  IR-IO-APIC   1-edge      i8042
  8:          1          0  IR-IO-APIC   8-edge      rtc0
  9:          0          0  IR-IO-APIC   9-fasteoi   acpi
 12:          4          0  IR-IO-APIC  12-edge      i8042
120:          0          0  DMAR-MSI   0-edge      dmar0
122:          0          0  IR-PCI-MSI 327680-edge      xhci_hcd
123:      25164    5760490  IR-PCI-MSI 1048576-edge      enp2s0
124:         17    5424414  IR-PCI-MSI 524288-edge      amdgpu

What I have compiled so far...

• Column 1: IRQ number
• Column 2&3: # of interrupts per CPU (variable # of columns depends on how many CPUs your system has)
• Column 4: Type of interrupt
• Column 5: ???
• Column 6: Name of device

I'm interested in finding out what data the 5th column contains, i.e. 524288-edge, and if someone can break down what the number represents. From researching online I only see the interrupt type column followed by the name of the device, this column data is always missing. Is it simply more information about the interrupt type?