Other worlds

The current (2010-4-13) count of known exoplanets is 452. Some have retrograde orbits.

"Turning Planetary Theory Upside Down: Nine New Exoplanets Found, Some With Retrograde Orbits", ScienceDaily, 2010-4-13

Since then follow-up observations and new survey missions and methods, particularly using transit photometry, have ballooned the count (2024-7-22) to more than 6,660 exoplanets. 

"Most Planets in the Galaxy Orbit Stars You Can't Even See", Phil Plait, Scientific American, 2023-4-10

Discovery of Exoplanets, Wikipedia 

Exoplanet dicsoveries by year and method (up to 2018)

https://en.wikipedia.org/wiki/Discoveries_of_exoplanets#/media/File:Exoplanets_discovery_methods_chart.png