Ministry of Internal Affairs and Communications monitors the price of eating out at a restaurant monthly.
The data below show the changes in the price indexes of eating sandwiches at a restaurant between 1975 and 2014, if the price in 2010 is taken as 100.
The next graph shows the changes in the price of one dish of sandwiche from 1975 to 2014.
Source is Statistics Bureau. 消費者物価指数 (CPI) 結果