The Congressional Research Service offers an overview:
President Reagan initiated this practice in earnest, transforming the signing statement into a mechanism for the assertion of presidential authority and intent. President Reagan issued 250 signing statements, 86 of which (34%) contained provisions objecting to one or more of the statutory provisions signed into law. President George H. W. Bush continued this practice, issuing 228 signing statements, 107 of which (47%) raised objections. President Clinton’s conception of presidential power proved to be largely consonant with that of the preceding two administrations. In turn, President Clinton made aggressive use of the signing statement, issuing 381 statements, 70 of which (18%) raised constitutional or legal objections. President George W. Bush continued this practice, issuing 161 signing statements, 127 of which (79%) contain some type of challenge or objection. The significant rise in the proportion of constitutional objections made by President George W. Bush was compounded by the fact that his statements were typified by multiple objections, resulting in more than 1,000 challenges to distinct provisions of law. Although President Barack Obama has continued to use presidential signing statements, the Obama Administration has used the interpretive tools with less frequency than previous administrations—issuing 20 signing statements, of which 10 (50%) contain constitutional challenges to an enacted statutory provision.I still believe that if you're going to use a signing statement to challenge a law, you might as well go ahead and veto the law. And certainly, conservatives have delighted in chiding President Obama for using the statements at all. (Their objections were mostly muted during the Bush presidency.) But if Obama is wrong to use signing statements in this fashion, it's apparently the case that he's only 1 percent as wrong as his predecessor was. Obama: The lesser evil!