0 years ago the Network Security landscape looked completely different, and subsequently at times it has evolved in quite striking ways. In the thick of the ongoing work of defending networks, it can be hard to step back to see the larger picture of how threats and defensive technologies change over time. How quickly do new threats arrive? How long does it take to actually deploy new security improvements? What do attackers probe for? How much encryption is actually in use, and how up-to-date is it? We'll provide a look at this landscape by drawing upon years - and in some cases decades - of huge datasets from a dozen large operational environments, illustrating how some changes are lightning fast - and others, glacially slow.