First off, welcome! Secondly, the administrative overhead is just one of many fees you get awarded at the beginning of every month. You get reimbursed for every employee, every aircraft, and every base. If you hover the cursor over the messages icon [It looks like a clock and a pencil.], you will see many more messages that scrolled below the display point. I personally wish the monthly financial report would be delivered as an email instead of pushing away messages that you might still want to see, but maybe that's just me.
To get a complete summary of your finances, click the leftmost tab "Organization Statistics" above the message display. If you are not getting enough financial tension, try playing on a higher difficulty level...