Rebuild or new chart (JFreeChart) to be used in a report in Pentaho Report Designer

The project consists in developing a complete new chart using JFreeChart to be used in a report in Pentaho Report Designer. The platform, presently in production, is made of different parts. The filling and source of data, a distributed console .net and a webpage gui in .aspx, to collect the data from companies (clients). The processing core of the system, the console and the Penthao Business Intelligence suite. The representation and delivery of the worked data, it is done by this last step with the ETL and the reporting engine, that uses a java IDE called Pentaho Report Designer which builds and uploads the created reports with the created charts to the BI server. We are focusing in upgrading the actual way to render one special chart within its report, because there is a problem with the data (x-values not equispaced but we need the position of the existing values to be equispaced for presentation requirements.. and space as there is a limit in the x-width) and we would like to define a new graph that solves the non-continous data we want to graph. Data series are kpi values for a company and a year, there are many companies and we compare one to the rest, we want to visualize the values of this compared company for the different years to the present (2014 if it is the last year of values) ones of the group. In a scatter chart this is done by puting in the x-axis the years, and the values of a particular kpi in the y-axis. The problem we want to solve is that we only need the years as labels, not as values! The years can be for a particular company, not in secuence and equispaced, like 2008, 2010, 2011 and then the control group (the rest of the companies that we have values) in the 2014 position. The columns should be equispaced although the values aren't. One approach we could discuss, as we are working perfectly with a scatter chart is to change the values using a sql query and then put the proper labels overlaping the equispaced changed values. Other ideas will be listened, and of course a new chart development with the above requirements also is an option. All access to online demo to the current system can be done using skype conference call to see the exact problem with the representation of the data with actual examples. We are developing the platform to a new level, we would like to transform it to a SAAS service, so this will be a first of more jobs related to it, we expect in short-mid term.