# Vehicle Attrition Rate from 1965?November 13, 2016 6:28 PM   Subscribe

Math Geniuses, I am trying to figure out how many trucks from 1965 may still be in operation. I'm using 2.5% totaled or lost per year, over 51 years. If there were 3250 produced in 1965, how many would be left today?

My Scout 80 Red Carpet Special was produced in 1964-5 to celebrate the first 100,000 Scout 80s made. 3250 were produced. I just want to estimate how many are left. I'm assuming a 2.5% kill rate a year. Is there a simple equation I can use on my calculator so I can vary the attrition percentage?
posted by atomicmedia to Travel & Transportation (5 answers total)

Best answer: Been a while since I tried something like this, but you take the survival rate, 97.5%, and multiply it by itself as many times as years (Y) that have passed, which is to say 0.975 to the power of Y.

Let's suppose the current model year is 2017, since those cars are coming out now or any minute now, so Y= 52.

0.975^52 is .268, so 26.8% of the 3250 should survive. That's 871 Scouts.
posted by Sunburnt at 6:35 PM on November 13, 2016 [1 favorite]

Response by poster: Excellent! Now I just have to figure out the real attrition rate (which could vary over time), and I will be dandy!
posted by atomicmedia at 6:40 PM on November 13, 2016

Yup. If you have the year-to-year attrition rate, you could just multiply each year's rate together to get the total rate. Just don't mix kill rates with survival rates and you'll be in good stead.
posted by Sunburnt at 7:44 PM on November 13, 2016

If you are looking for tables of vehicle survival rates, you might find some use in the DOE's Transportation Energy Data Book. They have tables describing such things by class, if not make.
posted by voiceofreason at 7:57 PM on November 13, 2016

Response by poster: And that is very hard, I don't think anyone has attempted to do that. Even the co-author of the "Scout Encyclopedia" has no idea how many are left. I can't even get any data from even this year.
posted by atomicmedia at 7:57 PM on November 13, 2016

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