Yes and no... Proportionally most departments respond to many more EMS runs than FDNY suppression. Most departments are sending companies to all EMS runs where they'll initial patient contact, stop the clock and then potentially wait hours for a EMS transport unit to be available. Of course FDNY send companies on the highest priority EMS runs, but with the exception of 10-99s, taking the door or carries they are probably going 10-91 in less than 10 minutes on 90% of runs. (Of course units have to take time to clean equipment, etc.)
Also most other departments are cross staffing the buses and are essentially EMS agencies that sometimes go to fires, while FDNY suppression is a fire department that helps it's EMS component as needed.
8-15% is a much higher than all but a few departments, especially considering that it is an incredibly dense urban setting, those aren't just private dwellings burning. It's not the War Years anymore (unless you're HM*1), but the FDNY is still a structural firefighting department