"Starting in 1990s, the growth in global methane levels began to slow down, and global methane became relatively stable over the period of 2000-2006. A resurge

"Starting in 1990s, the growth in global methane levels began to slow down, and global methane became relatively stable over the period of 2000-2006. A resurgence of global methane was not anticipated and came as a surprise." If it's been rising for centuries and is continuing to rise now, shouldn't the six year period of stability be the anomaly, not the fact that it's continuing to increase?