A wheat and oohh sooo close silver

Went back to the park where I previously found 4 wheat pennies.  Found #5 1957-d and I thought was a silver dime. It came out of the ground nice and shiny but with my luck - it was a canadian dime.  UGH!!!  Could not believe it - what the hell is a canadian dime doing here????  So it goes I am still searching for silver.  I noticed too that the further away I get from the ball field the younger the wheat pennies -  what does that mean????  The final count was 1-q, 1-d, 1-n and 5 pennies for 45 cents.

                                 2010 coin count
                                     Q-511
                               2 -  53,59-d washington
                                     D-585                             
                               4 - 1923,39-d,41,44 merc
                               2 - 1964,64d Rosie
                                    N -225
                               1 - V nickel - 1899
                               1 - buffalo - 1924   
                                    P - 957                            
                               1 - Indian head - 1864
                               55 - wheats  - 1910,15,20,24,27,34,37(2),38(2),39(2),41-d,42(2),44(9),45(3),46(2),47,48,49(3),50,51(3),51s,52(2),52-d,53,53-d(2),54,55,56d,(5),57,57-d(2),58,58-d
                               3 - Dol
                               1 - Half
                               8 - Foreign 
                                    2320 coins
                                $211.57 total
                                10 - silver rings
                              29 - total rings