A little more than a year has passed since more than 170 general counsel signed an open letter demanding that law firms field more diverse teams and threatening their collective millions in legal spend if outside counsel didn’t comply.

But gauging the success of the letter, and the subsequent advancement of women and nonwhite attorneys in the year since, is difficult and complex. Michelle Fang, chief legal officer of car-sharing company Turo, who penned the open letter, says she is hopeful that her fellow signatories have followed through. But would she bet her savings? No.