Speed up dashboard load

I create over 10000 invoices per month and no quotes. After the first month of use, the dashboard has become too slow to load, I guess due to the many invoices. How can I ensure that the dashboard loads faster regardless of the number of invoices in the database?

My thought was to have the program auto create new tables every month with specified prefix (e.g. ip_invoices_July2016) for the tables affecting dashboard loading (i.e. ip_invoices, ip_invoice_amounts, ip_invoice_items, ip_ivoice_item_amounts). Any ideas?

you might want to consider on doing a database dump…PLEASE BACKUP YOUR FILES AND DB BEFORE TRYING ANYTHING!!!