Aristotle's work on fish species is one of the earliest known. In the 1500s fish enjoyed a renewed interest in both France and Italy. 1551 saw the appearance of Pierre Belon’s "Histoire naturelle des estranges poissons marins", illustrated by woodcuts. In 1554 Guillaume Rondelet’s "De piscibus marinis" was published, also using woodcuts. Salviani’s work was published in parts over a period of three years. Its use of copper engraving was well-suited to depicting fish, and greatly superior to woodcuts with its lifelike rendition of eyes and scales. The copper engravings have a scientific appearance, but some details, like the correct number and position of the scales were omitted. Nicolas Béatrizet probably designed the title-page and the fish illustrations were made by Antoine Lafréry. Another theory is that they were drawn by the Italian painter Bernardus Aretinus and engraved by Nicolas Béatrizet. Salviani's "Aquatilium animalium" only deals with animals personally observed and handled by him. He collected most of the fishes for his studies from the market in Rome.
The World Bank has sponsored a project to curb air pollution through public transport improvements and the Mexican government has started shutting down polluting factories. They have phased out diesel buses and mandated new emission controls on new cars; since 1993 all new cars must be fitted with a catalytic converter, which reduces the emissions released. Trucks must use only liquefied petroleum gas (LPG). Also construction of an underground rail system was begun in 1968 in order to help curb air pollution problems and alleviate traffic congestion. Today it has over 201 km (125 mi) of track and carries over 5 million people every day. Fees are kept low to encourage use of the system and during rush hours the crush is so great, that authorities have reserved a special carriage specifically for women. Due to these initiatives and others, the air quality in Mexico City has begun to improve, with the air becoming cleaner since 1991, when the air quality was declared to be a public health risk for 355 days of the year.[citation needed]
With filming completed in Rome, production moved to Mexico City in late March to shoot the film's opening sequence, with scenes to include the Day of the Dead festival filmed in and around the Zócalo and the Centro Histórico district. The planned scenes required the city square to be closed for filming a sequence involving a fight aboard a Messerschmitt-Bölkow-Blohm Bo 105 helicopter flown by stunt pilot Chuck Aaron, which called for modifications to be made to several buildings to prevent damage. This particular scene in Mexico required 1,500 extras, 10 giant skeletons and 250,000 paper flowers. Reports in the Mexican media added that the film's second unit would move to Palenque in the state of Chiapas, to film aerial manoeuvres considered too dangerous to shoot in an urban area.
Cum nimis absurdum was a papal bull issued by Pope Paul IV dated 14 July 1555. It takes its name from its first words: "Since it is absurd and utterly inconvenient that the Jews, who through their own fault were condemned by God to eternal slavery..."

Question: What is daily subway ridership in the city where Spectre filming moved after the city where the author of Cum nimis absurdum died?
Answer: 5 million people