Since I began working at my current workplace, over half of the time I've spent there has been affected by the pandemic in one way or another.
ご質問ありがとうございます。
"Since I began working at my current workplace,"＝「現在の職場で働き始めてから」
"over half of the time I've spent there has been affected by the pandemic in one way or another."＝「私がそこで過ごした半分以上の時間はコロナにより何らかの影響を受けている。」
ご参考になると幸いです。
"For more than half the time that I've been at my current job, we have been affected by COVID 19."
"For more than half the time that I've been at my current job, we have been affected by COVID 19."
"for more than half the time" 「半分以上の期間」
"that I've been at my current job" 「今の職場になって」
"current job" 「今の仕事」
"we have been affected by ~" 「～の影響を受けている」
"Covid 19" 「コロナ」英語で"Corona"より"covid" と呼びます。
アメリカ合衆国 
オーストラリア 
