What does the following query describe? SELECT project_progress.Project_id, project_progress.Town, project_progress.Province, project_progress.Source_type, project_progress.Improvement, Water_source.number_of_people_served, RANK() OVER(PARTITION BY Province ORDER BY number_of_people_served) FROM project_progress JOIN water_source ON water_source.source_id = project_progress.source_id WHERE Improvement = "Drill Well" ORDER BY Province DESC, number_of_people_served