Seems like a misleading chart since there are both a left side and right side scale. I can’t tell which is which but my guess is it’s to make Texas stand out more.
The statistics indicate that Texas's share rose 1 percentage point from 7% to 8% across the entire chart, while California's rose about 4 percentage points from 16% to 20% before falling 2 percentage points to 18%. The lines do not want you to believe that.
(FWIW, I'm not even entirely certain I know what these percentages are of--the numerator seems to be tech jobs within a state, but is the denominator all tech jobs in the country, or is it all jobs within the state?)