From Wikipedia.
Patients with DNR therefore die sooner, even from causes unrelated to CPR. A study grouped 26,300 very sick hospital patients in 2006-10 from the sickest to the healthiest, using a detailed scale from 0 to 44. They compared survival for patients at the same level, with and without DNR orders. In the healthiest group, 69% of those without DNR survived to leave the hospital, while only 7% of equally healthy patients with DNR survived. In the next-healthiest group, 53% of those without DNR survived, and 6% of those with DNR. Among the sickest patients, 6% of those without DNR survived, and none with DNR.[19]
If you want a better survival rate for yourself do not agree to a DNR.
Years ago Wikipedia did not report on these stats.