I then thought about finding some data on the earths rotation around the sun and plotting it to see if it would show the same result. I found the Navy Data on this, and plotted the time between Perihelion date and time each year. Perihelion is the point of closest approach to the sun as was reported only to the nearest hour. This point of closest approach to my understanding is due to the resulting gravitational forces of all planets, asteroids and stars. Each planet has a different year so some times there is more pull or less pull depending on whether the planets are fighting against each other. As far as I can tell two actions are taking place speed up and slow down of earth in it's orbit around the sun due to the sum of all planets position. The other effect would be the movement of the actual closest approach point (Perihelion) due to the same forces. This would be a sooner or later time in the orbit depending on the direction of the forces.
Offered by Mike.