While the focus seems to be on Mercury, a number of planets retrograde every year. Some are long and slow which can have a greater impact (especially if it is in your sun sign) than the speedy turn around of planets closer to the sun.
13 Sun Sign Dates
Capricorn: Jan 20 - Feb 16
Aquarius: Feb 16 – March 11
Pisces: March 11 – April 18
Aries: April 18 – May 13
Taurus: May 13 – June 21
Gemini: June 21 – July 20
Cancer: July 20 – Aug 10
Leo: Aug 10 – Sept 16
Virgo: Sept 16 – Oct 30
Libra: Oct 30 – Nov 23