Store   sales1    sales2    sales3
                        1      62.1      61.3      60.8 
                        2      58.2      57.9      55.1 
                        3      51.6      49.2      46.2 
                        4      53.7      51.5      48.3 
                        5      61.4      58.7      56.6 
                        6      58.5      57.2      54.3 
                        7      46.8      43.2      41.5 
                        8      51.2      49.8      47.9