Is a flame spread index of 20 better than 26?

According to the State of Lousiana, pine wood is greater than 70 to 100 and inorganic particle board is 15 -20, therefore lower numbers are better. Please note that 20 seems to me to be close to 26, looking at various materials the difference isn't great. But 20 is more flame spread resistant than 26.

sfm.dps.Louisiana.gov/doc_flamespread.html