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Made in Taiwan.
The fourth digit in the serial indicates year of production (2000 or 2001). X in the serial indicates production Month (E to L - May to Dec). Y in the serial indicates production Month (A to D - Jan to April).
Mirra 540 Air model abbreviation is M54, 54 or MA.
Bikes made in Taiwan usually had an 5-8 month production and shipping timeline before they were sold in bike shops around the world. Bikes welded in the later months of the year would normally be made for the following year.