https://en.wikipedia.org/wiki/Age_disparity_in_sexual_relationships#Statistics

7.4% of married men are 10+ years older than their wives.

1.6% of wives are 10+ years older than their husbands.

25% vs 6% for being 4-9 years older.

0.3% of wives are 20+ years older than their husband; 1% for husbands.

Do these figures surprise you or fit into your worldview?