Between 1971 and 1985, which artist secretly made more than 240 works depicting his neighbor Helga Testorf?

Which "Godfather of Soul" had dozens of Top 40 hits from the 1960s to the 1980s but never a No. 1 on the Billboard Hot… Between 1961 and 1983, which nation sent many Venera probes to study the atmosphere and chemistry of Venus? From 1963 to 1973, which Florida landmark was officially known as Cape Kennedy? Between 1966 and 1975, which woman won the Wimbledon singles title six times and also beat Bobby Riggs? Between 1977 and 1980, which player won a state high school title, an NCAA title and an NBA title? Between 1978 and 1999, Pinin Brambilla Barcilon restored which masterpiece at Santa Maria delle Grazie in Milan? Between 1980 and 1990, the city of Gary in which state lost nearly a quarter of its population? Between 1982 and 1998, which Baltimore Oriole played and started in more than 2,600 consecutive games?