Hello! Does anyone knows how to tell the manufactured date/year of the Intel N80387SX Math Coprocessors codes?

For example I found this one on the net:

According to the owner the make and model:

N80387SX (16-25)
Manufacturing date: 14/1994
Manufacturing Country: USA

I'm trying to find out the dates of my two N80387SX (16-25) chips, codes: C2291685 and L5033155

Thanks for you input!

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