You can check the total number of pages fed through the printer. The information is printed together with the nozzle check pattern.
Select Maintenance on the printer's control panel.
To select an item, use the 
buttons, and then press the OK button.
Select Nozzle Check.
Follow the on-screen instructions to load paper and print the nozzle check pattern.
You can also check the total number of pages fed from the printer driver.
Windows
Click Printer and Option Information on the Maintenance tab.
Mac OS
Apple menu > System Preferences > Printers & Scanners (or Print & Scan, Print & Fax) > Epson(XXXX) > Options & Supplies > Utility > Open Printer Utility > Printer and Option Information