Fig. 1.

Linear regression analysis of H. pylori infection versus time (2003–2012). The calculated regression equation for the correlation of H. pylori infection (%) versus time in years from 2003 to 2012 was y = − 2.03x + 43.99

Linear regression analysis of H. pylori infection versus time (2003–2012). The calculated regression equation for the correlation of H. pylori infection (%) versus time in years from 2003 to 2012 was y = − 2.03x + 43.99