Does anyone know what the approximate normal lifespan of a regular incandescent (say 60 W, if necessary for an answer) lightbulb was back in the 1960s, 70s or 80s. Note - I am looking for the situation in former times, not what is currently specified for "now" lightbulbs.
Obviously, this would vary depending how often the lightbulb was turned on/off, and maybe other environmental conditions, but I am just looking for a very rough ballpark number, for a lightbulb that was, say, in a bedroom, or living area, somewhere where it would go on and off at least once a day usually, and often a couple or 3 times, and would be lit maybe 4 or so hours per day. Just a rough typical lifespan, like e.g.: "6 months", or "a year or so", or "5 years at least"...something like that, just from your memory of changing lightbulbs.