I've posted the chart above (courtesy of Turner) about 8 times now, because it's definitely a case where the picture takes less time than the thousand words.
Multichannel News did "the thousand words" version though focusing on all viewers, rather than just adults 18-49, and looking at the full year rather than just through August like the above chart, looking at prime-time versus total day and also looking at all cable rather than just ad supported cable - here are a 60 words or so:
Cable’s household share has increased every year since 2000 — the last time broadcast-network programming was watched in a majority of households. Back then, before cable networks began developing quality original scripted series and highly-rated reality programming fare, the four broadcast networks averaged a 46.8 household share compared to cable’s 41.2.
In 2009, cable’s 60.6 share was up 2% compared to 2008’s 59.2, while broadcasters’ 32.1 share was down 2% from last year’s 32.7.