Historic Exchange Rates of Mexican Peso and it's Decline

Today, the Mexican Peso is worth roughly 5 cents. I thought that the collapse of the Mexican Peso was the reason that millions of Mexicans immigrated to the United States over the last few decades. In order to research this further, I pulled up the historical exchange rates for the Mexican Peso.

To my astonishment, one Mexican Peso was worth about 40 US Dollars in 1980. It declined steadly until 1981, and then there was a massive spike downward in 1982 when one Peso was worth 17 US Dollars. The next big decline occurred in 1983 when one Peso was worth 8 US Dollars. I don't know what caused these massive spikes downward but there was a major earthquake in 1985 that killed 10,000 people in Mexico City and caused between 3 billion to 4 billion USD in damages. At the beginning of 1986, one Peso was worth 1.64 USD.

The next biggest decline I researched was the 1993 peso crisis. At the beginning of 1994, one Peso was worth only .32 USD.