Has human height been gradually decreasing since the time of Adam (peace be upon him), or increasing?

Allah Almighty created Adam (peace be upon him) with a height of sixty cubits. Then, creation continued to decrease until it settled at its current state. The proof for this is the Prophet's (peace and blessings of Allah be upon him) saying: "Allah created Adam, and his height was sixty cubits, and creation has been continuously decreasing ever since."