Feb 20 2018 3,007,383,866,429 4.62% 21,527,692,255 GH/s 
Feb 06 2018 2,874,674,234,415 10.43% 20,577,719,706 GH/s
Jan 25 2018 2,603,077,300,218 16.84% 18,633,553,122 GH/s
Jan 13 2018 2,227,847,638,503 15.36% 15,947,554,580 GH/s
Jan 01 2018 1,931,136,454,487 3.10% 13,823,613,194 GH/s
Dec 18 2017 1,873,105,475,221 17.74% 13,408,211,263 GH/s
Dec 06 2017 1,590,896,927,258 18.11% 11,388,083,790 GH/s
Nov 24 2017 1,347,001,430,558 -1.28% 9,642,211,820 GH/s
Nov 10 2017 1,364,422,081,125 -6.09% 9,766,913,694 GH/s
Oct 26 2017 1,452,839,779,145 21.39% 10,399,832,230 GH/s
Oct 15 2017 1,196,792,694,098 6.49% 8,566,975,802 GH/s
Oct 02 2017 1,123,863,285,132 1.85% 8,044,926,758 GH/s
Sep 18 2017 1,103,400,932,964 19.58% 7,898,451,536 GH/s
Sep 06 2017 922,724,699,725 3.89% 6,605,120,681 GH/s
Aug 24 2017 888,171,856,257 -3.80% 6,357,781,793 GH/s
Aug 09 2017 923,233,068,448 7.32% 6,608,759,726 GH/s
Jul 27 2017 860,221,984,436 6.92% 6,157,708,817 GH/s
Jul 14 2017 804,525,194,568 13.53% 5,759,015,666 GH/s
Jul 02 2017 708,659,466,230 -0.43% 5,072,782,052 GH/s
Jun 17 2017 711,697,198,173 4.85% 5,094,526,985 GH/s
Jun 04 2017 678,760,110,082 13.90% 4,858,754,124 GH/s
May 23 2017 595,921,917,085 6.42% 4,265,775,241 GH/s
May 10 2017 559,970,892,890 7.28% 4,008,427,786 GH/s
Apr 27 2017 521,974,519,553 0.22% 3,736,439,151 GH/s
Apr 13 2017 520,808,749,422 4.24% 3,728,094,244 GH/s
Mar 30 2017 499,635,929,816 5.03% 3,576,533,297 GH/s
Mar 17 2017 475,705,205,061 3.24% 3,405,230,497 GH/s
Mar 03 2017 460,769,358,090 4.54% 3,298,315,540 GH/s
Feb 18 2017 440,779,902,286 4.41% 3,155,225,442 GH/s
Just looking at https://bitcoinwisdom.com/bitcoin/difficulty
Feb 06 2018 2,874,674,234,415 10.43% 20,577,719,706 GH/s
Jan 25 2018 2,603,077,300,218 16.84% 18,633,553,122 GH/s
Jan 13 2018 2,227,847,638,503 15.36% 15,947,554,580 GH/s
Jan 01 2018 1,931,136,454,487 3.10% 13,823,613,194 GH/s
Dec 18 2017 1,873,105,475,221 17.74% 13,408,211,263 GH/s
Dec 06 2017 1,590,896,927,258 18.11% 11,388,083,790 GH/s
Nov 24 2017 1,347,001,430,558 -1.28% 9,642,211,820 GH/s
Nov 10 2017 1,364,422,081,125 -6.09% 9,766,913,694 GH/s
Oct 26 2017 1,452,839,779,145 21.39% 10,399,832,230 GH/s
Oct 15 2017 1,196,792,694,098 6.49% 8,566,975,802 GH/s
Oct 02 2017 1,123,863,285,132 1.85% 8,044,926,758 GH/s
Sep 18 2017 1,103,400,932,964 19.58% 7,898,451,536 GH/s
Sep 06 2017 922,724,699,725 3.89% 6,605,120,681 GH/s
Aug 24 2017 888,171,856,257 -3.80% 6,357,781,793 GH/s
Aug 09 2017 923,233,068,448 7.32% 6,608,759,726 GH/s
Jul 27 2017 860,221,984,436 6.92% 6,157,708,817 GH/s
Jul 14 2017 804,525,194,568 13.53% 5,759,015,666 GH/s
Jul 02 2017 708,659,466,230 -0.43% 5,072,782,052 GH/s
Jun 17 2017 711,697,198,173 4.85% 5,094,526,985 GH/s
Jun 04 2017 678,760,110,082 13.90% 4,858,754,124 GH/s
May 23 2017 595,921,917,085 6.42% 4,265,775,241 GH/s
May 10 2017 559,970,892,890 7.28% 4,008,427,786 GH/s
Apr 27 2017 521,974,519,553 0.22% 3,736,439,151 GH/s
Apr 13 2017 520,808,749,422 4.24% 3,728,094,244 GH/s
Mar 30 2017 499,635,929,816 5.03% 3,576,533,297 GH/s
Mar 17 2017 475,705,205,061 3.24% 3,405,230,497 GH/s
Mar 03 2017 460,769,358,090 4.54% 3,298,315,540 GH/s
Feb 18 2017 440,779,902,286 4.41% 3,155,225,442 GH/s
Just looking at https://bitcoinwisdom.com/bitcoin/difficulty