U.S Coins Shrinks when Years Passes.

  American's economy are shrinking down as time goes by, just like the coins did. The older the coins has been made, the more heavy and thick it is. Just like the value of money, the current of U.S dollar is lot less value than in the old days.
  Many people in now days stressing about money, and not having a job, and the problem is getting worse. I wondered if the U.S dollar will grow bigger again, or if the newer generation coin that came out will be even thinner?

FYI:
Cent - 97.5% zinc plated with a thin layer of copper
Nickel - A solid alloy of 75% copper and 25% nickel
Dimes, quarters, halves - 2 outer layers of 75% copper and 25% nickel bonded to a core of solid copper, for an overall content of about 92% copper.
Dollars - Manganese brass bonded to a copper core; overall content 88.5% copper, 6% zinc, 3.5% Manganese, 2% nickel
Source from: Answers.com