Very few are issued each year and there is reason why. Many people apply for K3 visa and once USCIS officer takes the file, they retrieve I-130 file from online which is easy to do and approve that application. Therefore, if USCIS takes 5-7 month to process K3, it can be beneficial to get I-130 approved sooner, than current wait time of 12 month+. This also explains why only 1-2 K3's are issued each year because it doesn't go to NVC stage since USCIS denies it by subsequently approving I-130 petition. Some people also argue that it is not fair to jump the wait line but I would say it is pretty smart to file K3 as it is free and you won't lose anything from its outcome and can only gain benefit of approved I-130 much faster.