The charts that are displayed on this page were built using the final data obtained from SWTOR's Leaderboards from the end of Season 3, which commenced with Game Update 3.1 on Thursday 12 February 2015 and ended with the release of Game Update 3.2 on 28 April 2015.
Note that the category "Tiers (Season 4)" shows the number of players in each tier based on their latest rating at the end of Season 4. However, for the tiered rewards, it's the highest rating achieved that counts, so more players than shown will have reached the higher tiers.
The Season 4 Swashbuckling Rewards can be seen here.
Choose between solo and group, then use the dropdown menus to pick your server (or all servers together), and which chart you'd like to see. This link can be copied to return to your current selection. Enjoy!