original: in the past 20 years or so , many new anchor designs have appeared .
simplifications: many new anchor designs have appeared over the past 20 years or so . many new anchor designs have been introduced in the last 20 years many new anchor designs have been made in the past 20 years or so . 1 . in the past 20 years or more , many new anchor designs have appeared . in the past 20 years or so , there have been many new anchor designs . many new anchor designs have appeared in the past 20 years . in the past 20 years or so , many new anchor designs have appeared . for past 20 years or so , many new anchor designs have appeared .