Question: Yoshinori Imaizumi is known for describing a subspecies that has been listed as critically endangered on the IUCN Red List since which year ?

Context articles: Yoshinori Imaizumi
Lion
Iriomote cat
Arabian leopard
Javan leopard
Indochinese tiger
Indian vulture
Endangered plants of Europe
South China tiger
South-central black rhinoceros

Yoshinori Imaizumi (今泉吉典 , Imaizumi Yoshinori , March 11, 1914 – April 2, 2007) was a Japanese zoologist.
 He is known for describing the Iriomote cat in 1967.
 He was the director of the zoological department of the National Museum of Nature and Science.
The lion ("Panthera leo") is one of the big cats in the Felidae family and a member of genus "Panthera".
 It has been listed as Vulnerable on the IUCN Red List since 1996, as populations in African range countries declined by about 43% since the early 1990s.
 Lion populations are untenable outside designated protected areas. Although the cause of the decline is not fully understood, habitat loss and conflicts with humans are the greatest causes of concern.
 The West African lion population is listed as Critically Endangered since 2016.
 The only lion population in Asia survives in and around India's Gir Forest National Park and is listed as Endangered since 1986.
The Iriomote cat ("Prionailurus bengalensis iriomotensis") is a subspecies of the leopard cat that lives exclusively on the Japanese island of Iriomote.
 It has been listed as critically endangered on the IUCN Red List since 2008, as the only population comprises fewer than 250 adult individuals and is considered declining.
 As of 2007, there were an estimated 100–109 individuals remaining.
The Arabian leopard ("Panthera pardus nimr") is a leopard subspecies native to the Arabian Peninsula.
 It has been listed as Critically Endangered on the IUCN Red List since 1996 as fewer than 200 wild individuals were estimated to be alive in 2006.
 The population is severely fragmented.
 Subpopulations are isolated and not larger than 50 mature individuals.
 The population is thought to decline continuously.
The Javan leopard ("Panthera pardus melas") is a leopard subspecies confined to the Indonesian island of Java and has been listed as Critically Endangered on the IUCN Red List since 2008.
 The population is estimated at less than 250 mature individuals, with a decreasing population trend.
 The total remaining habitat is estimated at only 2267.9 to .
The Indochinese tiger ("Panthera tigris corbetti") (Thai: เสือ โคร่ง อิน โด จีน , "S̄eụ̄x khor̀ng xin do cīn") (Vietnamese: "Hổ Đông Dương" ) is a tiger subspecies that lives in Myanmar, Thailand, Lao PDR, Viet Nam, Cambodia, and southwestern China.
 It has been listed as Endangered on the IUCN Red List since 2008, as the population seriously declined and approaches the threshold for Critically Endangered.
 As per 2011, the population was thought to comprise 342 individuals.
 The largest population unit survives in Thailand estimated at 189 to 252 individuals.
 There are 85 individuals in Myanmar, and only 20 Indochinese tigers remain in Viet Nam.
 It is considered extinct in Cambodia.
The Indian vulture ("Gyps indicus") is an Old World vulture native to India, Pakistan and Nepal.
 It has been listed as Critically Endangered on the IUCN Red List since 2002, as the population severely declined.
 Indian vultures died of renal failure caused by diclofenac poisoning.
 It breeds mainly on hilly crags in central and peninsular India.
 The birds in the northern part of its range once considered a subspecies are now treated as a separate species, the slender-billed vulture "Gyps tenuirostris".
 These were lumped together under the name long-billed vulture.
The list below contains plants that dwell in or migrate to any region in Europe and any nearby islands of the Atlantic Ocean.
 This includes plants that are found in the East Atlantic Ocean (Azores), Iceland, the Adriatic Sea, the Sea of Azov, the Black and Caspian Sea, Corsica, Cyprus, Palearctic, Russia, Eurasia, North African Coast, the Mediterranean Sea and islands located in the Mediterranean Sea, and the islands of Spain (Canary, Balearic).
 Twenty-one percent of Europe's vascular plant species (flowering plants, conifers and ferns) are classified as threatened, according to the IUCN.
 The list below was compiled from data on the IUCN Red List of Endangered Species (IUCN).
 The International Union for Conservation of Nature identifies species in need of attention before approaching extinction and works to increase prevention of extinction.
 The list below includes vulnerable (VU), endangered (EN), critically endangered (CR), and recently extinct (EX) species.
The South China tiger ("Panthera tigris amoyensis") is a tiger subspecies in the provinces of Fujian, Guangdong, Hunan, Jiangxi in southern China.
 It has been listed as Critically Endangered on the IUCN Red List since 1996, and is possibly extinct in the wild since no wild individual has been recorded since the early 1970s.
 Already in the late 1990s, continued survival was considered unlikely due to low prey density, widespread habitat degradation and fragmentation, and other human pressures.
 The name "Amoy tiger" was used in the fur trade.
 It is also known as the "South Chinese", the "Chinese", and the "Xiamen" tiger.
The south-central black rhinoceros ("Diceros bicornis minor") is a subspecies of the black rhinoceros.
 Although it was the most numerous of the black rhino subspecies it is still listed as critically endangered by the IUCN red list.
 Like other Black Rhino subspecies it has a prehensile lip and lives in savanna habitat.