Time series on Oregon State Rep and Senator

 So I have calculated the gerrymandering co-efficient for Oregon State Representatives and Oregon State Senate for the years from 2002 to 2018.  The co-efficient is stable for the State House of Representatives and does show that the re-districting resulting from the 2010 census had some effect in 2012.  The coefficient for the Oregon State senate is unstable.  One of the issues here is that approximately half of the senate seats are voted on every 2 years with possibly some special 2 year terms to replace vacancies.