How do we know that there is an insignificant amount of dark matter in the solar system?

Through the analysis of the rotation curve of how the velocity of the planets from the sun differs when it rotates, people can measure the distribution mass. 

Since the rotation curve decreases when the distance from the Sun is increasing, people can determine that Dark Matter is scattered along those distances. 

Catac, dry land,and lizards

The us is first  the  u.s. economy  remains the  largest in the world  in terms of nominal  gdp. however, the  u.s. economy  loses its spot as the number one  economy  to china when  measured  in terms of  gdp  based on ppp. in these terms, china's  gdp  is $23.19 trillion exceeds the  u.s. gdp  of $19.42 trillion