We love to make lists of where things are best or worst, improving or worsening. Persecution and martyrdom is one of the things we measure.
Measuring martyrs is the easier of the two, because in order to have a martyr someone has to die, roughly in conjunction with their faith--an event that doesn't actually happen all that often. Yet there is some debate about the statistics. The two numbers generally cited are those from the Center for the Study of Global Christianity (CSGC) and those from Open Doors (OD) et al. CSGC's numbers are quite large - over a hundred thousand martyrs per year - but show an average decline. OD's numbers are quite small - a few thousand - but increasing.
The disagreement is rooted the definitions. CSGC counts all Christians who die prematurely in situations of witness as martyrs (because, among other things, martyr comes from a word that meant witness in the New Testament): some percentage of people who die in religious wars are therefore considered martyrs, even though many might be not directly caused by their faith. (See their methodology, and a sample of martyrdom situations.) OD counts only believers who are killed specifically for their faith, so their numbers are much smaller (here is a discussion of the differences in methodology). There is a tension between these two numbers: the world is becoming "generally" safer for believers (regulation is more common than generic persecution) but in those places hostile to believers, a more intense danger is felt in specific situations.
Measuring persecution is more difficult, because persecution doesn't require death. It's a matter of degree of restriction of liberty. Different people have different ideas about what level of restriction constitutes persecution (as the firestorm of around Starbucks in the USA demonstrates). Pew Research has done good work in the area of quantifying different levels of persecution and quantifying it by country. Open Doors' Worldwatch List is similar.
Additionally, saying persecution is worse in a place can be measured qualitatively ("the possible penalties for faith are greater") or quantitatively ("more people are under persecution here"). Afghanistan has severe penalties for conversion to Christianity, but very few believers. India has somewhat less severe consequences for conversion, but far more believers under those restrictions. Both are, to me, valid ways of saying "persecution is worse."
When someone says "persecution is growing" or "persecution is worse" or "persecution is lightening," it's important to understand the definitions they are using. Two people can use different definitions and say completely different things about the exact same situation (in fact, CSGC says the martyrdom trends are improving, while OD says they are worsening--and it's because of this difference). That doesn't mean either is wrong; it could just be they are using different definitions.
We want simple statements, but the world is complex, and we have to live in situations of complexity.