There have been several studies completed that isolate just those facts. One study found that houses that were pre 1946 had much lower electrical fire causes then houses built 1946 - 1969, 1970 - 1991 and 1992 - 2003. In most cases the fire causation rate was twice as high for these later built house then the pre 1946 houses. In a study conducted by the Dallas FD and published in the New England Journal of Medicine(Vol 344, No. 25 - June 21, 2001) the fire rate causation of residential electrical was much lower 1900 - 1939 as opposed to each of the next five decades.
The fact is that fires are primarily caused by the residents of the houses themselves; cooking(primarily unattended food or frying), Heating(space heaters), smoking, candles, children playing with fire, intentionally set, accidental etc around 85%. About 15% are caused by electrical, storms, appliances(dryers) etc depending on what year you are looking at.
Residential fires are going to happen. The sad fact is many of the fatal fires happen at night with non-functioning smoke detectors. People either purposely remove the battery because of nuisance alarms or fail to replace them. Hard wired and interwired smoke detectors - now mandated for around a decade are having an impact but they are in a tiny percentage of the total housing stock.
Fire prevention is every homeowners responsibility. Turn off stoves and ovens if you become occupied with other things, supervise chldren and keep ignition sources out of reach. refuse to use candles(an ever increasing source of home fires), don't drink and smoke inside your house, don't use space heaters, use extreme care when using flammables, and get your home hard wired with smoke detectors. It is a relatively easy and reasonable cost job for an electrician. My 120 year old Queen Anne has code hard and interwired smoke detectors. How about your homes?