You’re reading Significant Digits, a daily digest of the telling numbers tucked inside the news. Happy Canada Day.30 percentPercentage of married households in which spouses have different political views. One third of those households involve a Democrat married to a Republican. [FiveThirtyEight]31 songsOf the 128 songs to hit the Top 40 this year, 31 were performed by women, 22 by groups of men and women, and the rest were performed by men.