If I include the years I studied it in school, then ~ years.
Including my school years, ~ years.
Including my school education, ~ years.
ご質問ありがとうございます。
① "If I include the years I studied it in school, then ~ years."＝「もし学校でそれを勉強した年数を入れるなら、～年。」
② "Including my school years, ~ years."=「学校の年数も含めると、～年。」
③ "Including my school education, ~ years."＝「学校教育を含めると、 ～年。」
ご参考に。
アメリカ合衆国 
