455 scripted TV shows in the US in 2016, up from 421 in 2015. My.
However, that general number's a bit quibblable since it includes English-language acquisitions, rather than just 'true' originals, as well as anything longer than 15 minutes on Vimeo, YouTube Red et al. Indeed, if we remove online services from the mix, broadcast TV is down by five shows from 2015 to 145, pay cable's down by one show to 36 and basic cable's down by seven to 181. Overall, everything's gone down since 2015 except online.
Whether that means that peak TV actually peaked in 2015 or we are seeing a true move by long-form content from broadcast to online, where there's an explosion of content starting, I couldn't say.
More details at Variety.