I have a pivot table with two columns: number of users who visited a website (impressions) and number of users who registered on the site (regs). The rows are for dates. I want to visualize the percentage of users who registered after visiting the site. Thus, I have the number of users for each cell as a value field, displaying it as percentage of impressions. Generating a pivot chart from the table, impressions and regs are plotted over date as a percentage of impressions. This means there is one line at 100% for impressions (always 100% of itself) and the graph for registrations below that. I'd like to remove the line for impressions, but when I set a filter to do so, registrations vanish as well, since the column for impressions is filtered from the pivot chart as well, turning the value field invalid. How can I just show registrations as a percentage of impressions in the chart?