Help! Stenographers which should I prefer to....

Hi I am Crispin Sarmiento 13 yrsold from the Philippines I am a Gregg Shorthand Begginner Im currently using the Gregg Centennial Edition but why there are using the anni and simplified edition what are the differences and more efficient to use the one im currently using or the others please state all the differences so i can prefer. And what is the difference of other editions of gregg, can a gregg centennial edition user can read older versions of  gregg what is the reason of these changes is shorthand valuable today?.should I continue learnig practicing it?   Favor Please send me a mailing letter of your Gregg Shorthand samples including the transcript in your own writing at any gregg editions u learn especially the centennial edition at my mailing address at " Phase 2 Buntong Palay., Silangan 1850 San Mateo Rizal Philippines            Thank You  hope for your letters ..........Thank you very much

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