Changes

* "The 4-5 digit reel number refers to the microfilm reel number of the assignment entry in physical USPTO records; similarly the1-4 digit frame number refers to the location of the assignment entry on the reel number in physical USPTO records. Thus, eachassignment recorded with the USPTO has a unique reel number and frame number combination. While both reel number andframe number are sequential, there are missing values in the sequence because each only specifies the first page of theassignment records and records may have multiple pages." from https://www.uspto.gov/sites/default/files/documents/USPTO_Patents_Assignment_Dataset_WP.pdf, pg12, footnote 38