In recent years there have been only about ten nuclear submarine patrols a year, each lasting three months at most and usually a lot less. Most have not gone far from Russian waters and some were by recently built SSNs (nuclear attack subs) or SSGNs (SSNs equipped with cruise missiles) and not by SSBNs.
The problem here was that the Russian Navy has not only shrunk since the end of the Cold War in 1991, but it has also become much less active. Much of the time at sea consisted of short range training missions, which often lasted a few days or just a few hours. But the true measure of a fleet is the "combat patrol" or "deployment." In the U.S. Navy most of these last from 2-6 months, and in the last decade U.S. nuclear subs have carried out ten times as many patrols as their Russian counterparts.
Currently, Russia only has 15 SSBN (nuclear ballistic missile sub) boats in service and not all of them have a full load of missiles. Some lack full crews or have key systems in need of repair. Twelve of the SSBNs are Delta IVs, which are overdue for retirement and rarely go to sea. Russia has only 15 modern, 7,000 ton, Akula SSNs (nuclear attack subs) in service. Actually, three are in reserve, for lack of money and crews, and another has been leased to India. The Akulas began building in the late 1980s and are roughly comparable to the American Los Angeles class. All of the earlier Russian SSNs are trash and most have been decommissioned. There are also seven SSGN (nuclear subs carrying cruise missiles) and 20 diesel electric boats. There is a new class of SSGNs under construction but progress, and promised funding increases, have been slow.
Currently, the U.S. has nine of the new, 7,700 ton Virginia class SSNs in service, five under construction, and 19 more planned. The mainstay of the American submarine force is still the 6,100 ton Los Angeles-class SSN. Sixty-two of these submarines were built, 42 of which remain in front-line service, making it probably the largest class of nuclear submarines that will ever be built. The Seawolf-class of nuclear attack submarines stopped at three from a planned class of twenty-nine. The 8,600 ton Seawolf was designed as a super-submarine, designed to fight the Soviet Navy at its height. Reportedly, it is quieter going 40 kilometers an hour than the Los Angeles-class submarines are at pier side.
The peak year for Russian nuclear sub patrols was 1984, when there were 230. That number rapidly declined until, in 2002, there were none. Since the late 1990s, the Russian navy has been hustling to try and reverse this decline. But the navy budget, despite recent increases, is not large enough to build new ships to replace the current Cold War era fleet that is falling apart. Since the end of the Cold War in 1991, most of the ship building money has gone into new nuclear subs. Six Akulas have been completed in that time, but the first two of a new generation of SSBNs, the Borei class, was delayed by technical problems, a new ballistic missile that wouldn't work, and lack of money. The first three Borei class boats, after many delays, are finally ready for service and ended up costing over two billion dollars each. The ballistic missile for the Borei was just approved last year, and there won't be enough of them to fill all the Borei silos for a year or more.
The Russian admirals made their big mistake in the early 1990s, when the dismantling of the Soviet Union left the second largest fleet in the world with only a fraction of its Cold War budget. Rather than immediately retire ninety percent of those ships, Russia tried to keep many of them operational. This consumed most of the navy budget and didn't work. There were too many ships, not enough sailors, and not enough money for maintenance or training at sea. The mighty Soviet fleet was quickly turned into scrap or rusting hulks tied up at crumbling out-of-the way naval bases.
While Western nuclear subs can last for about thirty years, Russian models rarely get past twenty. That means two new SSN or SSGN have to be put into service each year to maintain a force of forty boats. Unless the sub construction budget gets billions more dollars a year, that is not going to happen. Right now, the priority is on producing a new class of SSBNs (five more Boreis are planned or under construction). These Boreis are essential because they carry SLBM (Sea Launched Ballistic Missiles) that provide a critical (they are much harder to destroy in a first strike than land based missiles) portion of the nuclear deterrent. The rest of the Russian armed forces, like most of the navy, is in sad shape and unable to resist a major invasion. Only the ICBMs and SLBMs guarantee the safety of the state. So the way things are going now, in a decade or two, Russia will end up with a force consisting of a dozen SSNs and a dozen SSBNs.
The current fleet of nuclear subs is tiny and the Russians would rather keep them tied up at dock most of the time. The crews can do a lot of training at dockside and only go to sea a few times a year to check on their state of training. Given the number of accidents their subs have had in the past decade, the training the crews are getting now is not sufficient.