When Satoshi Nakamoto nominal first bitcoins in 2009, mine was a simple notebook and get a block for every 10 minutes as now. The Bitcoin algorithm automatically adapts to the complexity of the cryptographic task that miners have to solve in order to confirm the block and receive the reward, so on average it will always take about 10 minutes to find a single block. The more resources are added to the Bitcoin network, the higher the complexity. It is because of the complexity of the Bitcoin network is the most powerful and most secure in the World.