Is this what you are looking for:

    mysql> SELECT country, AVG(lat), AVG(lng) FROM c2014 GROUP BY country;
    +---------+---------------------+---------------------+
    | country | AVG(lat)            | AVG(lng)            |
    +---------+---------------------+---------------------+
    | ad      |  42.527902188508406 |   1.537318801102431 |
    | ae      |  24.891538320635465 |   55.51244805853463 |
    | af      |   34.04674051673764 |   67.26681304757301 |
    | ag      |  17.085518998526485 |  -61.79143601297681 |
    | ai      |   18.21587371826172 | -63.039283025832404 |
    | al      |  41.088975844950475 |  20.014610561816568 |
    | am      |   40.26937918217537 |   44.84238364011771 |
    | an      |  13.779007457889145 |  -67.10738386983765 |
    | ao      | -10.394024888552527 |  16.401272589394896 |
    | ar      |  -32.13739248870794 |  -63.40704697093584 |
    | at      |   47.62893757137828 |  14.375785999308414 |
    | au      |  -32.58224675171816 |  144.07049698825728 |
    | aw      |  12.509566132918648 |  -69.99144844386889 |
    | az      |  40.179647407439965 |   47.49281764155795 |
    | ba      |   44.13574533529882 |   17.93174898133396 |
    | bb      |    13.1662623028257 | -59.554101581004126 |
    ...
    | yt      | -12.817898351638043 |   45.14693607267786 |
    | za      | -29.213355151321988 |  27.271365789847575 |
    | zm      |  -13.74802438257624 |  27.937999186534476 |
    | zr      |  -3.150024081275917 |    23.1336162007831 |
    | zw      | -19.047764062703678 |  29.515317293888238 |
    +---------+---------------------+---------------------+
    234 rows in set (1.22 sec)