Since Bitcoin's genesis block in January 2009, more than 520,000 blocks and 17 Million bitcoin (BTC) have been mined and added to the blockchain. As of August 2018, BTC is officially unrestricted in 107 countries. Worldwide ten thousands of merchants accept BTC to exchange goods online and on-the-ground.
In 2018, the Bitcoin network consists of more than 8,800 nodes. Every node takes part in securing the network. The overall number of nodes can be seen as a measure of security. The higher the number of active nodes in the network and the higher the number of active participants, the more secure the Bitcoin blockchain is.
The next big step in Bitcoin's development is the successful introduction of the Lightning Network. The Lightning Network plans to operate as a second layer on top of the Bitcoin protocol and will enable special payment channels. Those payment channels will perform thousands of transactions per second, which will drastically improve the scalability of Bitcoin.
*Most of the abovementioned statistics can be found here.