Question:  Index of Effluency is the top prize awarded in a series of endurance races that  holds the Guinness World Record for what?
Context: Krishnam Raju Gadiraju (born 24 May 1989) is an Indian Rubik's Cube speedsolver and Unicyclist.  He is a two-time world record holder.  On October 19th 2014, Gadiraju solved 2,176 rubik's cubes with one hand in 24 hours and entered into the Guinness World Records.  On October 19th 2016, Gadiraju achieved his second Guinness World Record title after he solved 170 rubik's cubes on a unicycle, beating the former record of 117 cubes held by Owen Farmer, USA.  Gadiraju is also a memory athlete. David Andrew Farrow (born January 10, 1975) is a two-time Canadian Guinness World Record Holder for Most Decks of Playing Cards Memorized in a Single Sighting, entrepreneur, memory coach, speed reader and keynote speaker.  He is best known for winning the Guinness World Records for Most Decks of Playing Cards Memorized in a Single Sighting in 1996 and again in 2007 when he set out to reclaim his record after it was beaten in 2002.  The initial record was set at the Guinness World Records museum in Niagara Falls, Ontario, Canada while the latter was performed for Discovery Channel Canada at CTV Television Network studios.  Both records were accomplished under the controlled supervision of multiple cameras and multiple independent witnesses. Dave Holby (born 25 December 1980) is a British indoor rowing endurance world record holder.  On 18 December 2010 he became the first person to row the virtual distance around the earth's equator (40,075 km) on a Concept2 land rowing machine, setting a new Guinness World Record of 934 days.  The record appears in the 2013 Guinness Book of World Records.  He has raised over £40,000 for a number of charities, chiefly Breakthrough Breast Cancer.  In May 2011, he was awarded the Mayor's Medal for his contribution to the borough of Basingstoke and Deane.  In November 2012 he became Patron of Support through Sport UK, a national charitable trust that aims to use sport to change people's lives. Index of Effluency (or IOE) is the top prize awarded in the 24 Hours of LeMons automotive racing series.  General criteria to win this award is a car that is too unreliable to be driven effectively on the streets yet manages to complete a decent amount of laps on the race track.  IOE can be awarded to a vehicle that was deemed unreliable from the factory (e.g. Volkswagen Karmann Ghia) or a more reliable car with an unwise engine transplant (e.g. Ford Thunderbird with a BMW diesel engine). Alan Myatt (born 1957) is a town crier who set two Guinness World Records.  As well as being the loudest crier, recording a cry of 112.8 decibels, he also set the Guinness world record for vocal endurance, issuing a one-hundred word proclamation every 15 minutes for a period of 48 hours. The 24 Hours of LeMons is a series of endurance races held on paved road race courses across the United States, Australia (since October 2015) and New Zealand (first event held September 2016).  The series holds the Guinness World Record for the "Most participants in one race" (216 cars). George E. Hood is an ultra athlete, certified personal trainer (NESTA) and a Group-X instructor.  Hood also owns and operates a successful business known as Oceanside Paddleboard in Oceanside, CA.www.OceansidePaddleboard.com.  George holds 7 world records.  He has set a total of 6 Guinness World Records and one independent world record for the plank set in Beijing, China in June, 2014 which was certified in the media and by the Assist World Records organization in India.http://www.china.org.cn/wap/2014-06/24/content_32752425.htm George previously held the Guinness World Record for the prone hold, or plank at 3 hours, 7 minutes, and 15 seconds set on 20 April 2013. http://www.thepostgame.com/blog/eye-performance/201304/george-hood-sets-planking-record-again The 2012 European Le Mans Series was the ninth season of the Automobile Club de l'Ouest's European Le Mans Series (previously known as simply Le Mans Series).  Championship titles were awarded in five categories, with the Le Mans Series shifting its categories following its separation from the FIA World Endurance Championship.  LMP1 cars were dropped due to most teams entering the FIA World Endurance Championship while a new GTC category was created to allow single make grand tourer cars and FIA GT3s to compete in endurance races.  However, there were no GTC cars that competed during the season. Jennifer Rosanne Tinmouth (born 8 March 1978) is an English motorcycle racer.  She is the current female Isle of Man TT lap record holder, breaking the record during her first ever TT in 2009 and gaining a Guinness World Record for this achievement.  She then re-broke her own lap record during her second TT in 2010, with an average lap speed of 119.945 mph, gaining another Guinness World Record. Suhail Mohammad Al Zarooni (Arabic: سهيل محمد الزرعوني‎ ‎ ; born November 16, 1968) is an Emirati businessman and collector based in Dubai.  He is the second son of Mohammad Abdul Karim Al Zarooni.  Al Zarooni is best known for holding Guinness World Record twice for the year 2002 and 2003 for his collection of over 7000 Model cars.  He is the first ever Emirati after the Royal family of United Arab Emirates to be awarded with a Guinness World Record certificate.  Al Zarooni is also the largest collector of merchandise from Starbucks coffee.
Answer: Most participants in one race