<P> In 2004, the International Ski Federation replaced the calculation point as the measurement of the size of a hill with hill size . The hill size is the length from the takeoff in a straight line to the knoll and then along the level of the landing slope to the hill size point . The hill size point is calculated based on the technical data of a hill based on radius, angle of inclination and record distance . The calculation point or K - point is slightly further up in the hill and denotes the point where the landing slope is the steepest . It is still used for the calculation of distance points, which along with style points determine the winner of an event . For hills up to large, the scoring system grants 60 points to jumps which reach the critical point . For ski flying hills, 120 points are granted for the critical point length . Based on the hill's length, distance points are calculated, which are added for each meter beyond the critical point and subtracted for each point shorter than the critical point . A meter has more distance points in smaller hills . Hills also have a fall line; a jumper who falls or otherwise touches the ground with their body after the fall line is not penalized . </P> <P> The measuring of a distance in a hill was traditionally done by people who were positioned along the hill, who would signal where the skier landed . Today this is instead measured by an advanced video system, which allows measurements in 0.5 - meter increments . </P> <Table> <Tr> <Th> Class </Th> <Th> Construction point </Th> <Th> Hill size </Th> </Tr> <Tr> <Td> Small hill </Td> <Td> <45 </Td> <Td> <50 </Td> </Tr> <Tr> <Td> Medium hill </Td> <Td> 45--74 </Td> <Td> 50--84 </Td> </Tr> <Tr> <Td> Normal hill </Td> <Td> 75--99 </Td> <Td> 85--109 </Td> </Tr> <Tr> <Td> Large hill </Td> <Td> 100--169 </Td> <Td> 110--184 </Td> </Tr> <Tr> <Td> Ski flying hill </Td> <Td> ≥ 170 </Td> <Td> ≥ 185 </Td> </Tr> </Table> <Tr> <Th> Class </Th> <Th> Construction point </Th> <Th> Hill size </Th> </Tr>

When did they start using tracks on ski jumps