I've updated the graph, and maybe made it a little easier to read.
From Congresses 65 [1917-18] through 91 [1969-70] there were never more than 7 cloture votes in any two-year session. The line rising up from the bottom left of the graph shows what has happened to votes per session since. It's color coded by the party with the minority in the senate, Red for Rep, Blue for Dem. The yellow dot shows the 44 cloture votes to date for the current 113th congress.
Filibusters use is down from the 112 cloture votes of the 110th congress. But the 73 votes of the 112th congress is still above the pre-Obama high of 61 in the 107th congress. With more than a year left in the current 113th session, it was on a pace to exceed the total of the 112th. However, that will probably now not come to fruition.
Dems have used the filibuster, but typically about as often as the current norm. Reps have been responsible for the vast majority of the increased filibuster use over time. The squiggly red and blue lines [same color code, right scale] indicate the number of senators per party at a given time, counting independents who caucused with the party as being of that party.
It's pretty clear that abusing the filibuster has not been a problem over the entire span of the last century. It clearly has become one now. Filibuster use more than doubled as soon as BHO became president. Using it to block appointments has been particularly egregious, prompting the current change in senate rules.
For additional context, he alternating blue-red line at the top of the graph shows the sitting president's party affiliation.
I see Kevin Drum at Mother Jones has covered this subject as well.
The last straw came when Republicans announced their intention to filibuster all of Obama's nominees to the DC circuit court simply because they didn't want a Democratic president to be able to fill any more vacancies.
Cloture vote counts and make up of the Senate from Senate.gov.