You may already know that “The Cosby Show” is the top-rated program on television in South Africa. But do you know the number of pencils David Letterman tosses over his shoulder during an average show or the No. 1 selling seed each year for Burpee? The answers are in April’s Harper’s Index.

Portion of the world’s exports in 1984 that was imported by the United States: 1/5

Amount Bolivia earned on its exports in 1985: $1.1 billion

Amount of that accounted for by cocaine: $450 million

Value of British government assets that Prime Minister Margaret Thatcher has sold since 1979: $20 billion

Portion of El Salvador controlled by guerrillas in 1980: 1/4

Portion controlled by guerrillas today: 1/8

Percentage of white Americans who say peacetime military service is a “very important obligation”: 31

Percentage of blacks who say this: 45

Percentage of Democrats in 1955 who were black: 10

Today: 20

Percentage of Republicans in 1955 who were white Southerners: 10

Today: 33

Pounds of redfish harvested from the Gulf of Mexico in 1982: 2.4 million

In 1985: 5.7 million

Rank of Tenderpod Bush Snap beans among all seeds sold by Burpee: 1

Amount the average household spends on fresh vegetables each week: $1.74

Percentage of Americans who say they don’t know anyone who doesn’t like Jell-O: 55

Rank of “The Cosby Show” in popularity among all programs on South African television: 1

Total amount NBC’s four Thursday night sitcoms are expected to earn in syndication: $1 billion

Number of pencils David Letterman tosses over his shoulder during an average show: 4

Percentage of households whose television sets have remote control: 51.3

Number of spacecraft launched by the United States in 1985: 17

By the Soviet Union: 98

Number of seats on an American Airlines Boeing 727-200 before deregulation in 1978: 129

Number today: 150

Percentage change in the number of FAA-certified airlines since deregulation: plus 150

Percentage change in the number of FAA inspectors since then: plus 2

Portion of the top 250 industrial companies that had “golden parachute” plans for their executives in 1982: 1/5

Portion that have them today: 1/3

Percentage of Fortune 500 chief executive officers who say they “lose sleep over the competition”: 13.7

Hours the average American worked each week in 1973: 40.6

In 1985: 47.3

Amount the IRS claims John Walker Jr. owes in back taxes on income he earned from spying: $193,873

Percentage increase in the number of Americans planning trips to the Soviet Union in 1986: 54

New game shows offered to TV stations in 1985: 17

In 1986: 31

Season tickets to spring training games sold by the Los Angeles Dodgers in 1977: 630

In 1985: 3,300

Percentage of Americans who say that spring fever makes them sad: 4

Percentage who say they find life dull: 6